@Yakun13 From scratch, or playing existing animations. Forget about creating from scratch. Unfortunately, like anything else related to modding, you have to search for everything, most of it being pretty useless. Post here and hopefully someone can help. Just to get you started:

For existing animations:

Not 100% updated but 150,000 to play with:
https://alexguirre.github.io/animations-list/

Tutorials? Google is your friend.

Basics. Examples.

Ped.Task.PlayAnimation("veh@van@ps@music@motownidle_a", "idle_a", 8f, -1, AnimationFlags.Loop);
First part is the animation dictionary, second the name of the animation