Resizing video, landscape to portrait

Newcomer to DaVinci Resolve, fairly tech savvy, love the program. I want to resize some videos that are in a choir grouping. If I go to "cropping" and move the slider labeled "crop left" it moves the video in on both sides. Same with "crop right." If I grab the handles on the highlighted video, it makes the video smaller proportionally. If I hold down the shift key, it distorts the video in the direction that I move the handle. I did a couple little videos on my phone to show this, but basically my question is above. How do I bring the video in on the sides and get the aspect ratio I want? I may also want to make some portrait ones "shorter" to have them fit, so the same question there. Thank you.

Well, I can't upload the videos I made showing the problem I'm having, too large. Here are the links:
https://drive.google.com/file/d/1oBSNp3 ... sp=sharing
https://drive.google.com/file/d/1R0rfqx ... sp=sharing