GIRLS And DUDES NEED ADVICE?

So theirs this girl she's wut most people would call "she gets around" and my cousin's going to hook us up how is she going to act. From what i heard she's REALLY FREAKKY like she goes all da way and this is my first time im going to wear protection for sure and im nervous wut should i do im 15 and she 16 will she care how i perform should i tell her its my first time what wud the girl want me to say and please no mommy or daddy talk THANKS