My start was all the way back when WebTV was around in 1996. I was using IRC-like chat rooms provided by Talk City. There, we had fun trivia games, some friendly chatter and vice versa.
Then, I moved on to MSN Chat sometime in the early 2000s. I would make my home there until the day MSN decided to make MSN Chats subscription based sometime around 2004 and I ended up leaving. These chat rooms were where I had some of my earliest periods roleplaying.
From there I would go to MySpace and I stayed there for quite a bit of time, felt like maybe 5 or so years before I just gradually lost interest. By that point in the middle, when Facebook got out of its college-only phase, I joined about a couple years after that in what felt like 2008-ish.
In 2007 also, I was in DeviantArt chat rooms and I was there up until 2014. I would join Gaia Online too in 2007 until 2016.
I didn't start using things like Reddit until mid-2010s. I got into Second Life by 2013. Didn't use Twitter until much later and left long before Musk even got it.
Oh and somewhere around my ventures of the 2010s, I did in fact hop into mIRC servers for a bit.
And finally by about 2023, I jumped into the Fediverse for the first time via Lemmy, discarding Reddit for good (not that it mattered because I kept getting shadow-banned anyways). I do have a TikTok but it's only for associating with a friend on there. I've never regularly used AOL or Yahoo!'s chat rooms. I never had ICQ but I did have AIM, MSN and Yahoo!'s respective messengers. I've gotten into Instagram for a cup of coffee before bowing out like a couple days.
So, these days, all I use now is PieFed, Facebook, Second Life and Discord (if one can even call it social media).