Aerbabe,
I concur with both posts below. Until you have a piece of paper from HQAC confirming your commission you are not commissioned and ergo not entitled to wear the uniform, rank et al. I understand your desire to don a blue suit as quickly as possible but I would caution you not to act prematurely because otherwise you are in danger of putting up a serious 'Black'.
In my case the confirmation of my commission was one month after my Regional board, and I was not officially informed for a good two weeks after that date!
My advice to you is to go to this wing dinner in appropriate civilian attire.