I found out about tf2 in general from iaresnipar aka ma3la's videos
I decided I thought the game would be fun (I was 13 at the time) and I got the orange box for christmas in 2010.
I started playing Tf2 in january (after completing portal and playing a bit of half life)
Not long after I met competetive players in a granary pub, it was empty except for them. I played with them for a bit (it was a lot less playing and more of me trying to pass off as one of them (one of them was a hatless pyro, so I switched to pyro and remove my gibus and shit))
I learned that were competetive players and actually played with them quite a bit (they played a lot of PLR, which I have learned since is actually just a tdm gamemode).
As for competetive, I learned about it through these players but didn't really start paying attention to it until season 12. I played lobbies before that but I wasn't really part of it yet.
Since then I have taken frequent breaks but all the action that happened during s12 and i46 really did drag me in.
Shoutout to Jayskye aka Logic a long time friend of mine who was one of those players I met in that granary pub four years ago