My first munch was when I was 18 years old. It was in a city about three hours away but I didn't have much to do as it was the summer and I was a jobless bum at the time. I liked the long drive anyway.
I was probably the youngest one there by at least ten to fifteen years. I didn't talk much because there wasn't much I had in common with these people besides our kink. I think I stayed there about two hours before leaving and spending some of my time in that city shopping for other kink stuff. One of the older guys there gave me a bit of a creeper vibe though I think he may have just been an awkward person instead of someone with ill intent.
I've been to other meets since then in a closer city. Those were better because there were people that were somewhat closer to my age and shared interests with me. I'm still usually the youngest though(22). Second youngest abdl at a meet I met was actually someone from here on /abdl/!
It's a shame that most of the abdls in my age range are either too far to meet or too shy to come out to meet people.