These Pixel Art Animation tutorials are fun (and free) to watch

How to Animate Pixel-Art With Marmoset Hexels

Create Pixel Particle Animations in After Effects

Create a walk cycle (Free Project files) - Kashu

A Complete Guide to Walk Cycle Animation

How To animate a Walk Cycle part 1

Pixel art animation tutorial for beginners. Have a look!

Pixel Art Piskel Tutorials

How to Make Pokemon Pixel Art with Ease: An Ultimate Guide