Hi Jessica!
The Epcot International Food and Wine Festival is a great event. I try to make it to Food and Wine every year if I can. Generally speaking, the festival is every day of the week, but there are activities that are only offered on select days. For example, in past years, Disney has offered "Sweet Sundays" for an added fee, where a baker or pastry chef would demonstrate their signature desserts, which are served throughout the demonstration. Some of these special events sell out very quickly.
You can get more information on the festival
here. You'll want to look for this year's program, which won't be out until some time in the summer. When it does come out, you'll be able to find out when Disney is taking reservations for the special events. By the way, I suggest looking at the schedule for the "Eat to the Beat" Concert Series and seeing who will be performing when you are there.
Enjoy planning and write back if you have any more questions!