First, good on you for going. Second, you are right to be concerned. Mooh has told you how to "know your audience" above. My experience has been, and it's a good bit, that mostly anything you do will please them. They receive too few visitors and not enought attention. However, you'll receive the strongest reaction with songs they know. But don't let that stop you from going! Learn a few, maybe Bye Bye Blackbird, or The Tennesee Waltz. Then sing your favorites. You can search for the Hit Parade and figure your audience was 'young' in 1945. Remember they have enough sadness in their lives; they want to cheered up! If you sing songs they can pat their feet to and clap their hands a bit, you'll come away feeling like a million dollars. I would sing "Froggy went a courting" and "The Sheik of Araby" and "Folsom Prison". Good Luck.