My first was SUSE followed shortly thereafter by the initial release of Fedora Core. Lots of distro hopping and tinkering later, I run LMDE these days as my daily driver and I distro hop on the other computers in my collection.
My first distro was Slackware 4. Now that I'm old and don't got time for that, I'm running Linux mint on my main PC, 2 raspberry pi OS, and Ubuntu LTS for a Minecraft server.
Red Hat 4, father say me down on one of his Frankenstein computers built out of his trash heap in our basement and told me to have fun. I found tux racing konquest and played the shit out of them
Debian 2.2 "Potato" on a stack of floppies. If one was corrupted, you had to reimage it, and hope the download was good or you'd be sitting and waiting for a while.
Debian 2.x (don't remember exactly) was my first attempt. But I don't actually count that because after annoying driver troubles (networking and mouse) and having to recompile the kernel multiple times I unfortunately lost interest.
Tried again with Debian 8 on my laptop and stuck with it until I moved 100% Linux just a couple of years ago thanks to Valve/Proton.