If your child will be two when your vacation begins, then he will be free for the duration of your vacation. Package decisions are based on the guests age at check in. This is fantastic for you! We always loved to squeeze in as many trips as we could during that sweet free time - it ends soon enough, believe me!
As far as dining goes, your child will not be eligible for you to purchase a dining plan. However, he will be able to eat for free at any buffet or all-you-can-eat restaurant. This makes places like
Trail's End,
'Ohana,
Cape May Clam Bake, and most character meals a great value for you! For quick service meals, I think you will be pleased to find that most portions are quite large, so you could easily share your own food with your son. If he has a large appetite and you don't think this arrangement would work, you are also welcome to purchase him a child's meal out of pocket. (For dining menus and pricing, Allears.net is a very helpful site)
Have a wonderful vacation!