What to Expect...

I am doing my first Meet and Greet (with anyone ever) and don't know what to expect.  What happens at a meet and greet?  What kinds of items can be signed?  How fast do they move you through?  Can't wait to see the acoustic show, and I'm also wondering if the meet and greet will be smaller since the show all together is smaller.  Any thoughts on that?  Thanks in advance all you seasoned Shinedown fans!!!