Since we got polls, people have been asking questions about people's first fandom experiences online. And I've been answering with a very... common... understanding of what counts as fandom culture.
Which gets a result of X-Files, and Star Wars, and Biker Mice From Mars, and Animorphs.
But I was thinking about it just now, and I realized there's an earlier answer to what my first online experiences were.
Because back in the late 90s, when Ask Jeeves was a baby and Google was just born, Yahoo's search engine had an indexing system. With categories under it. And I found sites to look at not by searching, but by clicking through the categories and walking through the sites under "comedy".
In there were where I found the personal sites with things like parody songs. Early internet memes like "Mr. T Ate My Balls". D&D stories. Lists of jokes that would probably be considered boomer memes today. And also the programmers and geeks who were clearly the kind of people who would read the Hacker's Dictionary for fun.
(If you're not familiar it's literally a dictionary of old computer geek terms with a strong but esoteric sense of humor. Jokes for people who were computer programmers in the 90s.)
And that was the "fandom" experience I first had on the web. Trawling through these personal humor webpages for fun things. Even if I only half understood a lot of it and completely didn't understand some of it.
If not all of that sounds fandomy, a lot of it wasn't. But some of it was. And it contributed to who I am today.