My very first rp ever was a D&D Pen and Paper that I can't really remember well. That's been... 22 years ago.
My first LARP was - oh God I don't even remember the name. The name of the world we played in was "Eredia" though. Since I wasn't sure I liked larping I booked an NPC ticket. When I arrived at the castle where it took place the Orga Guys asked me if i was ok with playing the tavern maid - or rather...work at the tavern, since the original maid was sick. I got my money for the ticket back, and worked 72 hours straight as a bar girl. My feet hurt, my legs hurt, my everything hurt, i was SO tired I couldn't stand, I had not "played" one single minute but I had fallen in love with the hobby from watching. That was 16 years ago!
My first online written text rp happened on goreanchat.org. *grins* I remember that vividly! It was 17 years ago. I had read those trashy John Norman books when I was 14 (cause my dad had allowed me into his bookshelf then, thinking I'd read the Forgotten Realms book. The Drizzt do Urden novels. HA! He was sadly mistaken, i read every single book he had. Including the Gor novels!) and... i had been intrigued. Thinking back now I cannot see WHY i was so fascinated with them. But well. When we got internet I found this gor chat site, and registered immediately. It was set at a tavern. And basically all the rp happening was to play out how you served the Men drinks. I had imaged that a LOT of cybersex would happen. I was disappointed. And so i spend three years as "sura" earning my status from white silk to yellow silk to red silk tavern slave, only to have them change their ranking system, so I was doing the same with some braceletts. wood - silver - pearl - gold or something like that. But from there the path to text based erp was open and I have not regretted a thing ever since!