How to safely transfer iTunes library from MacBook Air to iMac M1?

I have a large number of songs that I bought over the years from

Apple. I also have a few that I ripped from my CDs. I had all of my music on and older Apple MacBook Air (2013) that started acting flaky, so I decided to move everything to my iMac M1. I copied everything to a thumb drive and then moved it to the iTunes folder. I am running into some issues and now wondering which of these files is correct and if I have something that needs to go. I have an iTunes Library .itl and an iTunes Music Library .xml. I also have a Music folder with a Music Library in that. Any suggestions are welcome.

[Re-Titled by Moderator]