We took our 2-year-old boy and 3.5-year-old girl to the rodeo last Thursday. We started out wandering around the livestock pens so the kids could experience what a cow looks and smells like up close, and then headed for the petting zoo to get personal with a bunch of goats. They liked that. There are a lot of food vendors -- fajitas, hot dogs, cajun, you name it. Typical carnival food. (In fact, they have a carnival, but we didn't go over there.) There is some indoor shopping for trinkets and whatnot, and an outdoor stage where bands play. My kids liked that. They also have a lot of farm equipment and various Ford vehicles on display, which my boy flipped over. I suspect yours will, too.
We didn't go in the main arena, either, but spent a good 3 hours on the grounds and had a great time.