How to make a First Person Camera with "Scriptable" camera type?

Any ideas on how to make a custom first person camera with the cameratype set to scriptable? I'm trying to simulate weapon recoil by rotating the camera up and having it return to its position. I figure just making an entire custom camera and applying everything I need on renderstep should be good since it would be easier to add things like sensitivity and more.

The problem is I don't know how I would make it where the camera will look around with your mouse.