How to implement animations to make them look Good?

Soo, i want to create TPS framework (third person shooter) but i never touched animations, of course i used them in the simpliest possible way, for instance play holding animation when tool was equipped and then disable it when unequipped, but still idk how to make animations where different parts of tool are animated too, or overall animations synced with tool actions, do you have any resources or tips what i can do to improve this?