If you're interested in creating 2D animation, you might want to take a look at the short film "Hero":
https://vidcommons.org/videos/watch/f5437dad-ceab-466a-97fb-550ead28563b
There's a brief set of behind-the-scenes clips at the end of the short to illustrate how it was made.
"Hero" was created on Grease Pencil, a set of 2D graphics tools in the open source graphics suite Blender.
Anyone can download and use Blender free: