I'm assuming you mean you have built a 3D scene in After Effects, and you need to cut between multiple camera angles within that scene.
Personally, I like to work with 3D cameras as separate layers. Remember that After Effects always uses the uppermost camera layer, so you can use a single layer for your main camera angle, then just use additional layers for the other angle(s).
Or, if you're determined to use a single camera layer, you can use Hold keyframes. You'll need to set a Hold keyframe for every parameter of the camera that you change. Then simply copy and paste the keyframes to the point where the shot needs to change. This is pretty straightforward if your camera positions are static, but can be a little more fiddly if your cameras are moving.