Well I can tell you where we ate it was our first time too.
MK- Cosmic Rays( more than enough food- you can really split this meal with a child) Really good to!
We ate a lot at the Food Court at All Star Sport where we stayed. The breakfast was really good! We never ate there for lunch though.
Most of the time we ate a big breakfast and than used our snack credits to hold us over till dinner. We normally ate dinner around 6pm. and it was always so much food that we were never hungry. When we would get dessert included we normally would get cookies or something so we could save them and eat them at a later time if we got hungry.
Hope this helps!
***One place to avoid is the Electric Umbrella in Epcot. ... A lot of food but, it wasn't that good. It was just burgers and fries but it wasnt that good.