Teens will laugh at you because:
(a) You're dressed funny
(b) You look like a geek
(c) You're simply there
If you're new you probably are showing it in body language - subtly, but animals and teens can pick up on that. They can smell nervousness a mile away, from upwind! Nothing you can do but ride, ride, ride and when you "own the road" they'll know it. And still flip you off once in a while.