Having trouble viewing animations in After Effects CC

I am having trouble viewing animations I've created, the speed of the clips run real slow

Ae is designed to playback cached frames in real-time. Space bar will only give you real-time playback if it's a very light project or you already cached the frames (the bar above your timeline should be green). what you should do is use the Numpad 0 shortcut to cache the frames before your preview and then play them back by typing 0 again or wait for the RAM storage to fill up. Type "preview" in the search field in the upper right corner of your Ae interface and read about it.

After Effects Version: 12.2.1.5 6% used of 4.0 GB 403 plug-ins Install RAM: 4 GB RAM reserved for other applications: 2.5 GB

4GB of RAM is the minimum requirement so AE should work. having a minimum amount of RAM mostly means you have a short duration of preview, but preview should still playback normal if it is cached to RAM.

about this warning:

This warning appears if you have the disk cache size set to greater than 80% of the available space on the drive. To make the warning go away, set the disk cache size to 80% or less of the free space on your drive, or like most of us - just click "never again" and don't bother with it. of course the exception is if you are using a system folder for a cache disk that is very low on disk space - you don't want to empty the system disk because of cache files so you should look into that if this is the case. I leave it ON to have an indication if I accidentally got my cache drive too full for some reason (say from unnecessary temp files).

having disk cache means your system can save previews to disk and cache them to RAM faster if needed so this could potentially increase your performance, but this is not essential in order to have a real-time playback of cached frames that should work either way.

about this warning:

it is for the ray-tracing feature which allows some 3D vector extrusions and some 3D bending of pixels layers in AE. this is an obsolete feature but you are using the 2013 version when ray-tracing was still something potentially exciting. considering how low on resources your system is, I don't expect you will be using this feature anyway so might as well ignore it.

if any of this still does not solve your issue, give us some more information on how exactly is your Ae preview behaving, try to isolate the problem and provide some screen shots or better yet - screen capture. 

What sort of animations are you creating?

What, exact, version number of AE are you using?

How are you trying to preview them?

What are your system specs?

How would you classify your experience with After Effects? Years? Months? Days? Hours?