That's why you shouldn't drive a 1969 Mustang project car immediately after getting your licence. You figure it out on a 2003 Honda Civic, then move on to bigger things when you have both the basic knowledge and the willingness and ability to advance your knowledge.

You claim that installing with btrfs failed. Did you look into what the error messages meant? You claim to not know what Flatpak is. Did you look it up?

RTFM is not just a thought-terminating cliché used by elitist wankers. It's a philosophy you have to live by if you want to play with powerful toys. Look at manuals, the Arch Wiki, Stackoverflow, or ask a clanker. If that's beyond your abilities at this time, you'll either have to improve yourself, or surrender for the time and try a more beginner-friendly OS.