Firstly, congrats on the move - South Loop is a great choice! You're walking distance from some world class museums and some great parks.
City of Chicago is also great in terms of grocery stores. Jewel Osco (part of Albertsons) or Mariano's (same parent as Kroger, more upscale than Jewel, but not as upscale as Whole Foods) might be walking distance from your residence. Unfortunately gas prices are insane in the city. But, if you're a member, Costco gas prices are much lower and are very close to suburbs pricing.
My only gripe about South Loop is that it kind of dies down in the evenings and weekends. Not quite like regular loop, but not as lively as Lakeview, Lincoln Park, etc. That it this might be to your liking, depending on where you are coming from. The good news is that you picked a good neighborhood, and you can always use this first lease as time to explore other areas should you be in Chicago for a longer period of time.
A food recommendation: Close to China Town is a place called Ricobenes. Their breaded steak sandwich is one of my favorite sandwiches in all of the USA - highly recommended.