There`s a Wamart Supercenter on Turkey Lake Road, much closer than the one PP mentioned, but probably not within walking distance, it`s 2.6 miles away. Short drive though.
There are Walgreens close, but again, I wouldn`t walk there. One is on Kirkman fairly close to PBH, and the other is on I Drive right opposite Endless Summer resort.
A cab/uber won`t cost much if you don`t have a car, I wouldn`t fancy walking from any of them never mind carrying any groceries you wanted.