When is the best time to do my audition..

When you're ready, just show up at the club and say you'd like an audition, be nice to whoever is working the door- they frequently screen girls for the managers.

They may ask you to come back on another night but they normally just put you on one of the side stages. One of the managers will watch you dance for a few songs then talk to you a little bit to make sure you've got a good attitude, etc.