hey there- I was really nervous for mine too, but it really wasn't bad at all. I was expecting a 2-hour toture sessions, but it was about 45 minutes of applicants discussing ideas around a table with the admissions officer. She asked us some basic things about ourselves, our undergraduate careers, experiences in the field, and some 'what would you do if...' type questions. It was honestly very laid back, and everyone was very nice.
Good Luck!