What are the different foods they have at the park for special diets?

Fiesta village is not a good place to eat unless you like fast junk food!!

Dairy Queen and the pizza place are the main places to eat there, but there are also snacks like popcorn and candy in the arcade. There are a few restaurants near by that might have more of an option with the mash potato kind of stuff you mentioned.

Do they have Vegetarian options and Mash potato kind of foods

what kind of diets food you looking for

Not sure, most regular theme park type food, burgers, hotdogs, can't, popcorn... a dairy queen, and a pizza shop with late of options...