Monterey upgrade caused several problems

Hello. I just bought a new M1 iMac and was going to trade in a mid-2015 iMac. I followed all the "trade-in" rules and wiped my internal drive then, after some problems, was able to install El Capitan. After I decided to keep that computer and trade-in a 2011 iMac, I upgraded the OS on the 2015 to Monterey (which I was running before I decided to trade it in). After the upgrade, I added two more users for the computer, and everything is working fine in their desktops, but when I sign into mine, the menu bar is missing (yes, I've changed the System Prefs a few times) but appears when I open something like System Prefs, but the Finder menu bar items don't show up, just the items that go with whatever I have open, so I can't change the Finder Prefs or View prefs. It also messed up the icons from my contacts, as well as the icon I use for iCloud...many of them are gone (along with those people's contact info in Contacts) or their icons are messed up, too. I see these problems the most when I use Messages even in another one of my computers. I'm running the newest version of Monterey. Should I reset the PRAM? I'm not sure if it's Monterey or iCloud but I notice these errors in all of my devices (iPhone, iPad, etc.). I've restarted several times.

Sorry this explanation is all over the place but I tried to explain exactly what's happening.

Thanks for any help...

Lloyd