Sorry, I should have clarified. I was just referring to the app/website www.meetup.com to make sure we're on the same page, you can sort by location, date, type (online/in person), distance, and category. There are many that are listed for specific age ranges, but honestly if you're looking to make actual friends then it's better to first look for shared interests, and then when you go, to start narrowing down to people in your age range when you're there. I don't know any in particular since you just named 'Maine' rather than a geographic location etc.