You'll meet interesting people who you might otherwise never meet. For many, that is the primary attraction. It has nothing to do with sex. I might have lost you on that one. Contrary to popular myth, the mere sight of naked bodies is not by itself arousing.
Arousal is a function of context and behavior.
Even with a lifetime of cultural conditioning that associates nudity with sex, therefore arousal, you'll find that it doesn't work that way. First time anxiety and the sensuous nature of the situation is balanced by natural social instinct. Your subconscious will know that this isn't the time or place for sexual feelings. Don't worry, your brain doesn't forget when it is the right time and place. But a day at a nude beach or at a nudist resort is neither.