How would I use mouse delta to move the camera when the mouse moves?

I've read plenty of forums and posts on how to do this, and watched plenty videos as well. The problem with those is that they have fixed positions with vector3 so things like Min/Max Zoom distance and LockFirstPerson won't work. I already figured out a way to lock my mouse to the centre, all that remains is so that it moves with my camera. Help would be greatly appreciated.