I'm sure you will like the Food and Wine festival. It will get crowded, especially the first and the last weeks of the festival. We usually go 2 or 3 times every year, and we try to taste something different every time. You pay at the booth, and since most purchases are for small dollar amounts, you just swipe your credit card and get a receipt. You don't even need to sign it. Of course, you can also pay with cash.
If you want to make it a meal, be prepared to spend a lot of money. The portions are very small for the price (last year it was around $4 per portion). We'll see what it is this time. We were planing on going tomorrow, but I think we'll go to Animal Kingdom instead because it gets very crowded on the first day of the festival.
The big question is: "How authentic is the food?"
A few years ago they had a booth from Peru, and I know peruvian food very well. The two or three different things I tried were very good, they tasted great, but I would have never guessed what they were if hadn't read what I had ordered. It was nowhere close to the real thing.
Enjoy the festival!