Great picture! is that one of yours?

I'd suggest finding the local chapter of the Sierra Club nearest you. You could go on some of their scheduled day hikes or weekend backpack trips. They also have youth trips (I think these are run out of the national group) and even some Inner City youth outings. The folks you meet on the regular day hikes and backpacks are likely to be older than yourself, but they would probably get a kick out of someone a little younger and enthusiastic as you sound like you are, and you in turn would probably enjoy their company. A young friend of ours, who is now 25, took a national youth trip with the Sierra Club when she was 14, and started hiking with the adult groups after that when she got really excited about the whole backpacking experience, which none of her friends shared at the time.