I have a video that I used the pan/crop tool to move and fit an image in the background. I want that video to zoom in on itself, not increase the aspect ratio, how do I do this? Also I heard that doing this will create black space on both sides of the video because it will conform the aspect ratio to the video, how can I fix this as well?
The only reference I have for what I'm trying to do is this meme, welp look here
Youtube link in case upload didn't work: 
(vulgarity warning)
If I understand what you want, "parent motion" may be the answer.
Another way would be to render the section you want to "zoom in on itself" and then use that on your timeline to zoom in using pan/crop or track motion.
Make the foreground graphic in photoshop (or similar) with a transparent cutout area for the video playing underneath. Save as tiff or PNG with alpha channel (no JPEG alpha channel). You can make underlying video zoom/scan/move however you like using event pan/crop or track motion.
If I understand what you're saying, while in Pan/Crop mode, you would zoom in on the pic until it fills the frame, then right click, and choose Match Output Aspect, and from there, move your cursor on the timeline, and zoom in to the point where you want to end the zoom. This should allow you to fill the frame and zoom in with no black bars on the side. Only issue is a drop in resolution and possible pixelation.