First off, welcome to the boards! It's always good to have a new Gill fan here!
Well, if you are anything like me, the meet and greet will be a surreal experience! I've had a fair share of run-ins with Vince, either as a meet and greet or chance meeting, but they've all been unique and cool! If you are doing an official meet and greet, there will be many others in the room with you, and you will have a few minutes (seems like seconds!) to chat with Vince. He's easy to talk to (unless your mind goes blank, like mine does in his presence!). I usually try to have a few things in mind to chat with him about, or questions to ask about a project he's working on or just completed. You can always ask about his golf game! There is usually time to get a thing or two signed, and then a snapshot of the two of you taken. The time goes by very quick, but he puts you at ease.
Enjoy, and please come back and share your experience here on the board! We'd love to hear a review of the concert, too. He won't be coming to my area anytime soon....
Most importantly, have fun!