Back up whatever data you want physically on your computer before doing anything. While still using your Mac os, take an external drive you are okay to wipe clean, then reformat it to an .ExFat file type (so both computers can read the drive easily)
I haven’t experimented too much with different distros, but I would say Ubuntu has a Macintosh feel to it to me. Linux mint is what I use for my gaming PC, and it works fine, but between Ubuntu’s and Mint’s terminals, I like Ubuntu’s way more. It’s a bit pedantic, but I just prefer it that way
As a software developer, it is a known best practice when you are using external software to use a specific version. Never use “latest” except in testing and development. Once it’s ready you pin it to a version ( which can be the latest version, just make sure to actually specify that version id). Then again I’ve never set up an *arr stack before