2D or 3D?
I can't use
_physic_process to use
move_and_collide because the function is outside of it
Not sure if I can follow... Which function is outside of what? Probably would be easier to understand if you had provided some of your code, but it doesn't really sound like animation solves your issue, first and foremost because it won't check for collisions.
all the tutorials online talk about Blender and stuff
That's because root motion is about "Blender and stuff": you animate a character in Blender and then import the animation into Godot. Never done it myself, but this video seems to give a good overview about how it works.