Easiest way to get started with full-featured puppet

I'm want to use Character Animator to put characters into a short explainer video, but I have very little character animation experience. I see that some things will "take care of themselves," such as facial expression and head movement (can be "performed" real-time). But I also want my characters to turn side-to-side (whole body), walk, have independent arm movement that's too complicated to use the mouse to create in real time, etc.

I watched several tutorials, but mostly they talk about creating your own puppet. I would be happy with a pre-canned puppet if it looked roughly like what I need (one child and one math tutor) but I can't find that, nor can I find a puppet that seems to have complete rigging ready to go for walking etc. Can I get some advice about where I can find such a puppet and a tutorial that gives me the basics to animate it?

One question not answered by the tutorials I looked at is: can arm and leg movement be input in non-real-time, like with key frames in the way After Effects would do?

... or if it's even a realistic goal to do this myself? (I could hire someone to do it, for instance, if it's too much for me to learn)