Dude just relax and be yourself..they'll probably do a test shoot with you (see how photogenic you are) and give you some pointers etc...dont sweat it..it's pretty easy..if they want you they'll want you..if not..well better luck next time...peace
ive gotten 2 modeling offers, but i am quite possibly the most unphotogenic person on the planet, so i didnt even bother going... so who knows, maybe they were scams?