I had a lot of terrible experiences early on. I got into d&d and larping through youth clubs at 13 and I met a lot of older teens and 20-somethings who wanted to act like rolemodels but were completely terrible people. These include, but were not limited to:>a 20-something year old depressed dropout who stalked and molested a 16yo girl I also played with. He also taught me a lot about what not to do as a gm>an older wiccan girl with pink hair who fed me beer at 14 and then snook up on me when I went to piss>another, very obese older girl who hit on me and my friends and flashed her tits and ass at us>a fat, older autistic-seeming dude who jumped a table and tried to kill me over some IC drama. He smashed his head into a wall hand had to get stitches
Slowly, I learned to get out of the club/lgs environment and only play with friends, carefully vetted people or people who are completely new to the hobby, and my enjoyment of the hobby increased significantly. The funny thing is, it's been my experience that the 'normal' and 'heteronormative' looking people are generally the pleasant ones, while dyed hair, leather clothes, tatoos, obesity and fetish-paraphenelia have become dire warning-signs for me.