Once you feel you are good enough you can start sending in resumes. A resume should include each different style of dance that you know and how long you have been doing it, and it should also include all prior dance experience.
A good way to get experience is to get yourself in as many different things you can. Local theater groups are a great way to gain experience. Getting a job as a dance instructor Is also a good way to gain experience and practice at the same time.
By sending your resume to all the different casinos you can greatly increase your chances of getting at least one audition. Do not expect to get hired at the more popular casinos on your first audition. The bigger Las Vegas casinos usually like to hire girls with more experience, so you will probably have to work as a showgirl at a smaller casino first. All of the big Las Vegas casinos put on shows to attract crowds to the casino, and instead of hiring new dancers every time the change the show, they hire full time dancers and these girls are called Showgirls.