Creating an entity that shoots a custom projectile by pressing F, then a cooldown.

Hello, i was making a tank mod and i was wondering, how do you make it so that the vehice can shoot a custom projectile once you press F, and make it so that you cant spam it?

I have seen a lot of forums around this topic, but none help, i get the idea of what i have to do, but i don't understand how.

Any help is appreciated :)