I don't know how your voice is so I really can't help with suggesting a song. I'm not sure how the theaters are in your area are, but where I live singing a song from the show your auditioning for is Taboo! Also Acappella auditions are frowned upon. Also if you use a cd track, make sure it does not have any other voices on there. You may contact the place your gonna audition at and ask them what you need for auditions, if they have a cd player,and if they piano or accompanist. Hope this helps
Break a leg!