I like to tell people who are new/scared of computers that breaking stuff is part of learning. And those are seem like wizards with technology probably have the most cyber-skeletons in their closet.
Biggest "whoopsy" I've ever done was actually back on my first laptop running Windows Vista. 12yo me went on the hunt for "free frame-rate" so I could play Minecraft at higher than 15fps So I looked into overclocking and of course since I was a dumb kid, I didn't try incrementally increase the clock/power draw and instead just cranked everything to max...Yeah I didn't have a computer for a most of the year after that.
As for dumb stuff I've done on Linux, Well I once spend most of a day compiling Librewolf from source because I didn't know how the AUR worked yet. That and un-mounting my boot drive while trying to mount an iso image through the terminal one time...maybe twice...