Chrissyann - congratulations on getting to go to head office - it's an awe-inspiring experience (I was up there last July for Man of the Year).
You will have a fantastic day - and hear so many inspiring stories (and the food is wonderful).
Just enjoy the day, try not to be nervous (think of it as a large Image Therapy session), and have a wonderful time.
(oh - take a few spare tissues - it's hard not to get overwhelmed by hearing everyone's journies)