Either record camera movement (hard to do but if you can trick the key recorder to do it, you can make the camera move however you want it). Things to be bypassed: Sometimes, when you move the camera towards one angle while it has mixed angle sizes ( in example a camera looking down but at 190 degrees), if you want to rotate the camera to the left or right, it will rotate in the opposite direction. To fix this, you first straighten the camera on let's say frame 1 and record that. Then move slider to frame 10 for example and move your camera to left or right and down at the same time and record that. Then go back to frame 1 where your camera sits normal and make it look down at the same angle that it was looking at frame 10. Record that. Now your camera should be both watching down and moving left or right without going in the opposite direction or doing a spin. Can also just use frame 2 for straightening the camera instead so that you don't have to go back to 1 and rearrange it). After that, just delete frame 2 and there will be just frame 1-10 doing the rotation. Pretty annoying, huh?

OR
use motion path, I've heard it's simple but all the tutorials around here confuse me too much so I found the 1st way easier.