

My first was Ubuntu 14.04. and then 16.04. at school 💀. as early as 2015 iirc
Though Blackbox or Kali might be a contender too (one of the distros my father had installed for fun)
I had rly cool CS teachers, which also administered our infrastructure
then we used Linux Mint in the “Linux” club run by one of said teachers
For personal use, my first one was Manjaro in 2018 (I switched to it with a Windows dual boot, I got rid of Windows entirely in 2020 I think?). Somewhere I switched to Endeavour OS, tried out OpenSuse Tumbleweed on my laptop and eventually settled on Fedora bc of the Grub fiasco Arch had. Am using it to this day.
Though it’s in the form of Nobara on my desktop; I also plan on switching to Bluefin eventually
Nowadays it’s easy AF pretty much everywhere nowadays. Sometimes there are simple GUI tools that get you there with just a few clicks. Hardest it will get is having to look it up in a wiki for the distribution you are using (if it doesn’t have them preinstalled) and then following simple step-by-step instructions