celestialfawn These extra files are duplicates likely created by OneDrive, which is syncing the contents of your Sims 4 user folder along with everything else in Documents. (The blue arrows in your screenshot mean syncing is in progress.) Do you want or need OneDrive? If not, I would strongly suggest getting rid of it. Various options are covered here:
📓[GUIDE] [PC] Managing OneDrive | EA Forums - 12636625
You can of course delete the duplicates, but if you don't do anything about OneDrive, you'll probably get another mess like this before too long.
As for how to clean up the mess, you can actually set aside the entire folder, start the game once to create a new (clean) folder, and only move over the files you'd like to keep. That would be the contents of saves, Tray (saved households and builds), Mods if you use mods or custom content, perhaps Screenshots and Recorded Videos, and Options.ini if you don't want to redo your in-game settings. Everything else is extraneous and will be recreated as necessary, so you can trash it all.
All files and folders with extra characters in the names are duplicates the game can't read.