...I was surprised, but can't imagine I'm the only one who has experienced this. How do other folks deal with this anxiety/sense of sticking out?
Sure I was nervous my first time out. That's why my first time out was in another city altogether. But I figured out pretty quickly how much fun it was and never looked back. As others have suggested, you have to assume the attitude of confidence whether you feel it or not. Eventually, you discover you have it without even realizing it.

Regards,
Rex.