This part will go in depth with working with keyframes.
Lets say you have a nice stick and you want to have a zoom on the medal.
First sync the medal's appearance with the music perfectly.
Bring the bar up to right before the medal. (make sure the clip is selected)
in the effect controls window, expand motion. Click the stopwatch next to motion and the one next to scale. this creates 2 keyframes, which you can see in the right side pane of the window. (they appear as diamonds)

slide the bar to the point in which the medal appears.
now make the scale 117, and the position 372x228. in the pane where you see the keyframes. move the ones on the left so there is some space between the frames.
drag the timeline further one, make scale back to 100, position 360x 240 (default)
move these keyframes to the right the same distance as the ones on the left.

play with the position of the outside keyframes (always keep the center ones in their place) until you get a preview of how youd like. the distance between all the frames should be the same to ensure a smooth zoom.