Model audition for Quinceanera Dresses, What to wear?

Tomorrow afternoon, I'm going to audition for Quinceanera Magazine because they are holding an expo in about a month, and are looking for girls to model some dress. I have no idea what to wear, as of right now I have this dress, that has a black tanktop, and a coral colored bottom. The dress has the fabric of one of those high-low dress, however, the dress ins't that style. It's about to my ankles in length, and I plan to layer it with a black knit cardigan I got from forever 21, and some dark brown heels. Do simple make up, and my hair in a pony tail. But I feel like everyone will show up in jeans and some sort of top..Help?