Hi Erika,
Okay, we've seen this sort of thing several times before. What you're seeing is the screen's frame that's supposed to come off when you remove the screen. However, what happens is, if you don't remove the Pentalobe screws, the frame remains very securely fastened to the chassis and you end up just removing the screen without the frame, leaving the frame on the chassis.
So the frame is still there, secured by the stripped Pentalobe screws. You're going to have to find a way to remove those screws, whether that's done by using a screw extractor, a Dremel on the frame, or drilling out the screws, they have to come out so you can get the old frame off the chassis. Once the screws are out, you can go through the screen removal process again, this time working on the frame all around the edges of the phone until the frame comes free.
After that you'll be able to put the replacement screen in. Here's another answer that demonstrates the issue.
Replacing my iPhone X screen but it's different than videos show - iPhone X - iFixit
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
1
crwdns2947414:01crwdne2947414:0
Could you share some pictures to see what we're working with?
crwdns2934271:0crwdnd2934271:0 Jesse Hooton crwdne2934271:0