2Cute – First off, you have nothing to worry about because HaKadosh Baruch Hu runs the world. To calm down a little bit, I recommend getting some slight exercise (run/jog for a mile or so). When you see him just be nice and smile. He’s going to ask you questions about yourself, family, interests, etc. and you should do the same.
The most important thing to remember is not to worry. Hashem runs the world! You’re fine. Hatzlacha Rabbah!