Is there a grocery store within walking distance from downtown disney or anything within walking distance from pop? THANKS:)

There isn't one from Pop - and I'm not sure about DTD, though if there is one, it's probably going to be overpriced. You might consider a grocery delivery service (if that's the kind of store you mean). There's a thread about water savings in the Everything Else forum (were I moved this to) that talks about the idea of grocery delivery.

Going off of what Drince said, there really isnt one within walking distance. My take is that if you really need to get some supplies for your stay, a delivery service is going to be worth the extra charge.

Besides, you can spend a lot of extra time and go shopping or you can pay a small fee and enjoy the parks while someone else does the shopping for you.

From DTD if you walk straight down Hotel Drive (those hotels on property but not Disney hotels) turn a bit to your right when you reach the end and there will be Public's. It is the store the College Program kids often go to.

We used to use it when the kids were little, also many restaurants in that arena too. If you take a bus to DTD and walk I'd take a cab back to Pop.
Lugging groceries is a chore. My cab fare from POR to Vista Way (college program dorms) was $13.00 + tip. It was about 3 blocks farther than the grocery store. Just depends on if you want to go to a park the day you arrive. My hubby would stay with the kids and go to the pool and I did a quick run back then.

If you are looking to buy small amounts that you can carry on the bus, you can walk across the street from DD to the Hess gas station with a food mart. My DD and her BF did this while there without a car. They bought snacks and soda and beer after they finished in DD and then walked right across to the bus stop and returned to the All Stars. When I asked here for advice I was told that the Publix at the Crossroads was too far to walk and too dangerous, and was made aware of the Hess, which was new at the time.