I think the fastest way to learn about pixel art is to see some assets that is already finished and then copy. after that you might want to see some pixel art base they are really great and quick way to do it. Its okay to be stiff because pixel art are very limited. Then, you might want to see some tutorials on youtube on how to do it.

I recommend you to sketch your character around 32 x 32 pixel. under than 16x16 pixels u will get limited very quickly, but its still doable. don't be bothered by law of physics

your animated gif is great. My advice for animating hair and hand is trial and error and just do it.