One of my favorite places near Creighton is California Taco. It's completely unhealthy but so delicious! It was once featured on "Diners, Drive-Ins, and Dives."
Here is their website: http://www.californiatacosandmore.com/
Creighton is also pretty close to the Old Market in downtown Omaha and there are a variety of great restaurants down there. My two favprites are a little French place called La Buvette.
(Their website: http://labuvetteomaha.com/) ans M's Pub (http://www.mspubomaha.com/).
Welcome to Omaha! Hope you have a great trip!