Help please with intro!!

Hello, When I set the key frame then move them cam then set key frame and play that it moves thru that How can I make it just show one part then the other here is an example listen to the song and when it zooms in to one part how can I do that but for the whole thing

If you listen to the heart beat part that changes the cam if I do that If im in one place then key frame that and move and key from it moves along it does not change instently how can I make it do that?