Have fun.. if it is geared to a younger age group then you are more than likely not going to be the only one who is participating for the first time. Not only that, but most will probably feel self-conscious initially.
I did the first time I went to a nude beach, but once I realized how much I was enjoying myself and how friendly people were I got over it.
I just got back from an awesome weekend, I had no problem going all the way soon after I arrived once the main group of other people and a friend who I hadn't meet arrived. There were many new comers and non of us had any issues going all the way right from the beginning.
If a nudist event is for you, you won't even realize you are naked 15 minutes after you strip down. I am unaware of anyone that keeps their penis at half mast to appear to be more man than they are, so don't put too much pressure no yourself. The nudist lifestyle is really carefree, others gave great advice with footwear, towel, and sunscreen.
Yea soon after everyone is naked you start to pay more attention to faces and conversation since you don't really have anything else to look at, and you can't be like it was that guy in the orange shirt.
Also you end up talking to people who you would probably never get the chance to talk to in a clothed setting, for instance I had a really great conversation with a guy who's training to become a doctor.
In this setting it was a mixed setting with women and men, which didn't turn out to be a problem at all, and i'd say 95% of the participates where straight and they had no problem at all with the fact that me and my friend and possibly a few unconfirmed guys were gay, some even asked me to tell them about my coming out and everything and were genuinely interested in the struggle that it was.
You defiantly would not want to attempt to try to keep yourself half hard it would be so inappropriate and after being there for like 2 minutes you realize how many variations there are in things such as cock size.
I mean there were guys who looked like they had no dicks at all, then there was the hung uncut guy, and the hung cut guy. Did seem as though my dick is extraordinarily unique, as I didn't really see any others that were loose cut, they were either totally uncut or totally cut with no skin covering the head at anytime, and you saw ones that stick straight out, ones that hang down, there were also a few different circ styles high and tight I would say was the most prevelant however. So I just must have had the weird doctor that used the plastibell or whatver on me.
We went to a nude beach also though I'm going to have to say that I enjoyed the experience at where we camped better, as it was a more relaxed environment and there seemed to be more safeguards in place to prevent gaukers and creaps from staring, there were so many gross people eyeing all of us down at the beach it wasn't funny, one guy was even putting his hands down his pants, though it did seem as though the police and beach volunteers were concerned about this type of behavior, and advised us on future visits to report it right away so these people can be removed from the beach.