Purchased iTunes albums missing on older 2017 iMac and new Mac mini after automatic upgrade

I own an older 2017 iMac that worked pretty well. Did everything I wanted until Apple decided a couple of months ago to upgrade even after I had all the boxes checked to not have automatic upgrade. So now my Mac is slower and dumber. Nothing works right.. I have bought several albums off of iTunes in the last several months. Went to play one on my iPhone and come to find out it aint there. Went to my media folder on my iMac and they aren't there either. None of them are. Went and checked the preferences for iTunes and looky there, box is checked to send purchased albums to the media folder in music. Well that sure as heck doesn't work. Bought a new Mac mini and did an immigrate. A third of the albums I have in iTunes in my iMac bothered to load into the new Mac mini. What the ****. Macs used to just work. Now you need a phd to get anything to work. And since its AI everything. I've come to find out that's probably the problem. I just like to know where the albums I paid money for to you are stored on my Mac. If they are at all.

[Re-Titled by Moderator]

Original Title: Help