I am 17, and, play airsoft fairly regularily. It was a little rocky at first, but many of the players in my area now know me, and are fine playing with me.
A few points of advice.
1. Keep a low profile, Don't post unless you have something that is legitimately valuable to add. People seem to like to target minors for meaningless flame.
2. Grow a thick skin. People will be harsh, especially to minors.
3. Deeds, not words: If you an prove that you are a mature, reasonable person, I would be surprised if hosts had serious issues with letting you play. (in a few years) However, people have come on these boards before, seeming like completely mature minors who then freak out. To be taken seriously as a minor, you have to show that you really are mature.
4. Get your parents involved. The first few games I attended, I was required to have a parent/guardian/older family member present. They still have to sign the waiver if I am playing at a paintball field, but they don't have to play with me anymore.
5. Read. See all the stickys? Read them all. Theres an insane amount of very important legitimate information there. Read it all, and don't ask a question unless you really can't find an answer.
6. Use the Search function, Don't make new threads about subjects that are common knowledge. People don't mind helping new players answer questions, but not if the question could be answered by the new player doing a 30 second search, or a quick google.
7. Airsoft is not a cheap sport. If you buy low end stuff to start, you will regret it down the road. I am probably close to the 2K mark invested in this sport, and I see no end it sight. Get a summer job, and don't waste your money on cheap crap.
Last one. Be polite, don't be pushy. As minors were generally not welcome here. It sucks just taking it, but getting yourself in fights and arguments will just end badly... Sometimes is a good idea to back down from conflicts.
Follow these steps, and I would be surprised if hosts in the area would have any issues with you playing when you turn 16 or 17.
If you have any questions, feel free to PM me