What I would recommend is either getting a new hard drive and swapping it with your current drive, or creating a back up disk image of your current computer on an external drive. That way your old computer is safe if you mess anything up. (You probably won’t need it tho, it’s not as hard/scary as it initially seems).
Linux has very recently become much easier to use. The current version of WINE (a program which allows you to install and run Windows programs on a Linux PC) is incredible, so you really shouldn’t lose anything capability-wise in the switch either.
If you just add a Windows partition on your current disk, Windows 11 will randomly delete the entire Linux partition (I’ve read about this happening to multiple people). So you’d want a clean installation of Linux to avoid Microslop’s spyware and malware.
I still have the old hard drive with my Windows 11 system on it, but I never needed to use it, and I’ve been switched for long enough that I would not use it now… I should wipe that drive and put it in an enclosure to be an external