Total Noob Questions . . .

Software does not make a good animator - keep this in mind. To become a good animator, you will need to learn animation, not software.

Chenjil is right in mentioning The Animator's Survival Kit (Expanded Edition) by Richard Williams: get it, read it, re-read it, and learn from it. If you are REALLY serious about becoming a (character) animator, you could (should?) also consider getting the DVD set (which is 50% off till today):

The Animator's Survival Kit Animated

Or check with your local library whether they have it. There's no better reference or master course. Richard guides you through it all.

Another great resource are Preston Blair's books. The original publication is available here:

https://animationresources.org/instruction-preston-blairs-advanced-animation/

Also get the new edition (which unfortunately doesn't include the original characters of the first release).

This is part of a free online course. You'll have to put in the work, though.

Now for software. Before you pick one of more animation apps, you need to learn a bit more about how 2D animation is done with the help of computers nowadays (I am not covering 3d animation, btw).

Two main approaches:

1. traditional frame-by-frame animation. All frames are drawn by the animator(s).
   • Paper based Method 1 (Vector): the animator starts on paper, scans each paper drawing, the software cleans up the scans and converts to vector strokes, of which the widths and placement can be adjusted and the look finalized, and are then coloured.
   • Paper based Method 2 (Bitmap): the animator starts on paper, scans each paper drawing, the software is used to clean the scanes, but NOT converted to vector strokes, and remains bitmap. This allows for more painterly effects and more freedom in visual style of the final animation.
   • Paperless Method 1 (Vector): the animator uses a graphics tablet and/or drawing monitor to sketch, draw, and colour all frames directly using vector tools.
   • Paperless Method 2 (Bitmap): the animator uses uses a graphics tablet and/or drawing monitor to sketch, draw, and colour all frames directly using bitmap-based digital painting tools.
   • Rotoscoping: real actors are filmed, and the animator draws over these frames as a reference, adding additional elements and details, or removing parts.
2. Cut-out characters and inbetweening
   • an animated character is drawn in segments, and assembled together as a virtual puppet. Each segment can be re-used and replaced by other elements in order to make character turnarounds and expressions possible, or change the character's clothing, etcetera. Parts are parented to other parts so that when the head is moved, all the facial parts move with the head.
   • hinge-based simple parented cut-out characters at the very least support forward kinematics: the animator selects the upper leg, rotates it, and the lower leg rotates with upper leg. This is fine for robotic and simple movements, but creating a convincing walk cycle may take a lot of effort.
   • more advanced software supports inverse kinematics: when the animator moves a foot or hand, the entire body (or main parts) respond in a (more) natural way, which makes it relatively simple to animate organic looking natural movements. For example, to have the character reach over with their entire body, only one of the hands needs to be moved, and the rest of the body follows that movement.
   • depending on the software and the complexity of the character, it may be relatively simple up to very technical and complex to create virtual puppets.
   • the resulting animation almost always looks less convincing and natural compared to well-executed traditional frame-by-frame animation. On the other hand, production time may be dramatically reduced, and inbetweening is taken care of automatically by the animation software.

For any animated film any one and any combination of these techniques may be used, and the animator(s) may not necessarily limit themselves to just one piece of software. It depends.

That is why you must think before you do. If you drawing skills are wanting, and you still want to animate, than traditional frame-by-frame may be too daunting a task. Drawing should be second nature. But time (production time) may also be a limiting factor. The type and artistic style of your animation may also be a deciding factor. It all depends.

Which is why it is a Very Bad Idea to limit yourself to any singular piece of software for animation. Animation skill stands by itself, and is a very particular skill. The software used is but a tool to speed up the process. Software will not make you a good animator (rather the opposite in my experience).

So what kind of software is there, seen from the perspective of the two major computer 2d animation workflows?

• Adobe Animate CC: Quite good simple to use vector drawing tools. Terrible bitmap drawing tools. Animation tools are okay, but are surpassed by other software. Relatively straightforward to get started. Rather difficult to get away from that typical "Flash" animation look. Cut-out characters are a hit-and-miss affair. The IK tools are pretty bad.
  The lack of proper bitmap digital painting tools prove a limiting factor for backgrounds, for example. You will need to create those in other software like Photoshop.
  Still very popular in various quarters, mainly because Flash used to be so incredibly popular in broadcast animation, and because it is a relatively easy to use animation app that has proven itself in actual production (and still does). Lagging behind the competition, although various plugins exist to ameliorate some of its shortcomings. Adobe is finally putting in some effort to improve Animate CC's animation tools. It's slow going, but at least they are trying again.
  Good for vector based frame-by-frame, reasonable for vector-based cut-out characters, but with plugins it is quite nice for this purpose (up to a point). Doesn't directly support a smooth paper-based workflow. Forget about effects, particles (rain, snow), etc. There is hardly any support in Animate CC for these things, and you will have to use After Effects for this. Animate CC is generally not the tool to finalize the animation in, and relies on tools such as After Effects and Premiere to do so.

• Adobe After Effects: although meant for visual effects, can do some quite good cut-out characters animation with plugins like Duik, Rubber Hose, and Puppet Tools. Complex compositing and effects are readily available, as are nice particle effects. The main drawback is that any assets (drawings) must be done in external software.
  Good for effects, particle effects, and cut-out characters with Duik. Good all-in companion software for effects and compositing.

• Toonboom Harmony. The industry standard in the West. Production proven. Toonboom replaced Flash in most studios due to the stagnated animation tools development in Animate CC (well, that's part of it at least).
  Advanced and Premium accommodate both paper-based and paperless animation workflows very well.
  • Harmony Essentials. Vector drawing tools only, and bitmap drawing/painting tools are missing. Of all three editions this one seems to be aimed at beginning animators, and is quite limited in scope. No cut-out characters. Give this one a wide berth.
  • Harmony Advanced. Good vector and bitmap drawing tools. Great animation tools. Effects are limited. Quite reasonable for cut-out characters work, although for more complex work you really need the node editor which is only available in Premium. Good all-round animation app for serious animators.
  • Harmony Premium. Same as Advanced, but with additional studio production tools and a node editor. Very good for cut-out characters and control, but you will need to know scripting to make the most from it. Lots of compositing and visual effects, and particles for wind, rain, explosion, and other effects. Expensive. Full end-to-end animation production enviroment.

• TVPaint Animation: bitmap digital painting and drawing based. No vector tools. But very, very powerful for traditional frame-by-frame animation and excellent digital painting tools. Proven in production. Effects are available, particles, post effects. Storyboarding in built-in, unlike the competition. Rotoscoping tools. Works for both paper-based as well as paperless animation workflows. No cut-out character tools. Full end-to-end animation production enviroment.

• Moho Pro: vector-based animation software, with no bitmap painting tools (bitmap assets can be imported though). Excels in cut-out IK driven characters which are easy to set up and automated. Arguably the best in its class for this type of work. Some effects. Vector drawing tools are good, although somewhat different compared to other software. Production proven.

• OpenToonz: open source and free production level animation software, used in Japan for feature length animation films. Used in the production of some of the best 2d animation. Quite nice vector drawing tools and good bitmap painting tools. Excels in paper-based workflows and production management, similarly to Harmony Advanced and Premium. Like Harmony a complex animation tool. While cut-out characters are supported, the workflow and tools lag behind both Moho and Harmony, but still quite usable compared to AnimateCC. Full nodal effects, particles, compositing are all available in OpenToonz and, just like Harmony Premium, the animation artist will be able to produce and master the entire animation in one environment without the need for additional prep tools. Full end-to-end animation production environment.
  Teams up with ClipStudio EX to mitigate some of its drawing shortcomings. Mac version is still somewhat unstable and problematic. Be sure to download the latest releases from GitHub: Releases · opentoonz/opentoonz_nightlies · GitHub

• ClipStudio EX: while originally comic production oriented, now part of a number of Japanese and Asian animation studios' pipeline due to the rather first-class and as-yet unbeatable drawing and inking tools and their "feel". The EX edition supports quite nice traditional frame-by-frame animation, but lacks advanced animation production tools. That is why CS EX exports directly to OpenToonz. The animation workflow may take some effort to understand. Vector tools and bitmap painting tools are supported.
  For the traditional frame-by-frame animation artist the OpenToonz/ClipStudio EX combo proves to be a very powerful combination.

• Krita: open source and free digital drawing and painting. Not geared towards full animation production, bit excellent drawing and painting tools with good frame-by-frame animation options. Good to have as a companion app.

• Photoshop: similar to Krita, good to have as a companion app in the animation process.

• CelAction2D: production proven animation tool used primarily in UK animation studios (as far as I am aware). It single-handedly saved the UK animation industry (it is said). Very powerful animation software in the same league as Toonboom and OpenToonz in terms of production workflow. CelAction focuses on cut-out virtual puppet character animation, and assets must be created in external software (vector and bitmap are supported). Like Moho Pro, it focuses completely on rigged cut-out characters, and excels in this animation workflow. Not suited for frame-by-frame consequently or a paper-based workflow. Arguably the best animation tool for end-to-end cut-out animation. Full end-to-end animation production environment.

There you go, lots to choose from. If you are starting out, test some of the waters out there. The choice of your animation software really depends on your specific requirements. When I state Full end-to-end animation production enviroment, it means the product is suitable to produce the entire animation without the need for external mastering and/or finalizing software (like a video editor, or additional effects software). You may still need assisting tools while in production. For example, CelAction2d doesn't have any creation tools, so you would have to create the assets to build characters within CelAction2d in an application like Photoshop or Illustrator.

I haven't touched topics like lipsync tools, or audio production. Some of the aforementioned animation tools include lipsync options, others rely on external tools. Audio tools will be needed as well, since none of the animation tools have good audio mastering and editing tools, if any at all.