Melee fight

I want to make game about hunger games and i want to make very unusual fight system:
In every game when you left click you hit someone exacly where your crosshair is.
I want to make a system that when you are holding left you need to slide mouse like a real weapon (faster=higher damage) (if you hit neck (fast) you can cut of head etc.)
And the same with deffence-when you hold right you can move your mouse (weapon) where you want to dodge.
I need to know:
-How to make this system
-How to make animations for moving weapon
-How to make hitboxes
-How to make animations like cutting of head, hand etc.

That’s first person game

If anyone know how to do that please tell me down below

Thanks for all help !