Okay i have a modeling shoot on wenesday and i am really nervouse any advice?

its a all natual glamour photo shoot and they said that you just have to be your self this is my first modeling shoot and i am only 13 so i am going to be the youngest one there getting photos done all the other girls are 16 or 17 and they are all going to be watching me get my photos done wich is making me more nervouse got any advice that will give me more confidence which is what i really lac in