What to do at pool parties?

my first pool party is in 2 days and it's a girl boy party (i'm 13)and i'm REALLY nervous. Idk if i should even swim because people that r coming have never seen me with my hair curly and it gets CRAZY curly after i swim. and idk what to wear around guys... im patetic but i need help!!!! oh and im not hosting it,idk how many ppl r coming and i think its in the afternoon if that helps...