So Im a bit older but I started going to the con at your age. (oh I am feeling so old right now only twenty and I feel like I need a cane) but any ways the greatest thing about the con is for the most part just walk up to people and start talking to them. I have met one person in the seven years I've been going (again that feeling of being old) that was out right rude to me. 
have fun kiddos.
To add to this comment, I've been attending for a few years and can confirm that it is just amazingly easy to stand in a line for a few minutes for an event and walk away with a new group of friends to spend time with at the con and afterwards. People are just really friendly and everyone wants to meet new friends and talk about their shared interests. Seriously, don't be shy, almost everyone you walk by will want to strike up a conversation.
