What should I wear on a first date to the movies ?

So I'm going on this date with this guy that my friends hooked me up with we have talked and everything but idk what to wear I'm going shopping Friday so I could get new clothes . We are going to go see transformers at the end of the month . I have never met him but my friend and her boyfriend who is his friend is coming with us , I got a big butt and bog thighs so I got curves so not everything can work for me please help .!! Btw I'm 14 .