The Club has a couple (literally, TWO) spare helmets that people can use for rides. However, no guarantees that they will be available at any point in time, so if you can bring your own, that would be better.
Jon, we can get you a ride, but you have to be 16 first....track rules, not ours.
If you can grab a recent (SA 95 or M95 or later) helmet, I'd suggest doing that prior to coming to the track. With your own helmet, I have a better chance at guaranteeing someone a ride.