How do use region3 for hitboxes?

Alright so instead of using .Touched I decided that I wanna use region3 (unless there’s a better method?) however I’m not exaclty sure how to use region3.

I’m making a 2D fighting game and the only weapon is a hat which you use as a projectile (you can throw the hat) so I’d make a region3 around the player and then I’d just detect if the hat part touches it so do I make a region3 as soon as the player joins? or only when I need it? And like how do I detect if something touches it. And I think that’s all I need to know?