It all depends on the complexity of your project…
Like xpgained said, it’s fairly simple to make by using bools (CanFire, IsFiring, IsReloading, etc).
However as you make some progress and things start to get more complicating, you might wanna consider making the weapon an actor on its own, add an inventory and a save system.
If you are new to unreal I recommend that you look up some tutorials.