Do they have a concession stand or little eateryof some kind?

Yes

Yes. Kiosk and such throughout the park ( at Carousel and in the zoo itself)

Plenty of places to eat inside

Restaurants are open daily April through September from 10:00 am to 5:00 pm and include The Wilderness Café (Open Year Round), The Serengeti Market Café (Open Seasonally), and The RiverCamp Sweet Shop (Open Seasonally).

Yes several.

Several!