I also was 15 ! And everyone was at least 18!
They didn't laugh at me, most of them didn't even know. But sometimes they asked me out to a club and then I had to tell them I couldn't because I had to be 18 to come in. And then they asked "how much months untill you are 18?" and they were really surprised when I told them 2 years
But they were very nice to me, and we always had fun.