It depends on what you want to buy. If you just want milk, cereals, bread, drinks, water bottles, and snacks, there's a Target at S. Harbor and Chapman.
And while you're there...there's a $1 Store next door to Target in the same plaza that sells Disney souvies (for the kiddies). They have notebooks, pencils, pens, stationary sets, etc. We always go there so DDs can bring stuff home for their friends.