There is a Super Target off of 417 which is the route I think most shuttles and taxi services use to get you to Disney.
There is also a Publix close to Disney property right on 192, just off of the main disney road--I think it is East--and there is one off of Narcoosee Road which is located close to the airport.
There is Super Wal-mart--but it is a bit down 192 and not as easy to get to when you have valuable vacation time at stake.