It looks like your null ref is coming from your character controller and not the camera controller. Run a simple test: -assign your cameraChange script to a box and disable the mesh renderer -set the collider on the box to "Trigger" -assign your two cameras to the CameraChange script -create a capsule, set its tag to…
Mountains: it should be as simple as dragging/dropping your cameras to the cam1 and cam2 variables within the inspector. i'd recommend learning the basics of unity scripting if you're having trouble here https://unity3d.com/learn/tutorials/modules/beginner/scripting/variables-and-functions if you're still having trouble…