Special Melee System

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 !

That idea is basically mouse based fruit ninja.
Totally doable

Learn game design, then Unreal Engine

learn a modelling tool. I recommend Maya LT, they have student editions you can hone craft

again learn game design and animation

or get a guy

Yeah im trying to learn everything but i dont know where to start. I learn ue4 from youtube but there is nothing about this system.
Do you recommend something ?

Learn how to make fruit ninja with a mouse.
Your mechanics are very similar.
This has all the documentation you need to make something in UE4. Read it all and study them.

Good luck