Does the museum have a cafeteria? Or do people typically bring their own lunches, or eat near by? Ive never been there before.

Yes, but they only have vending machines. Bring lunch.

Yes, there's a cafeteria, but you can bring food with you.

There is a lunch room with vending machines. Not enough for a meal but definitely a wide variety of drinks and snacks. There isn't much in the immediate vicinity but it's a short drive to many restaurants. If you're planning to stay a while I'd bring snacks or sandwiches for the kids.