In my fictional attempt at surviving a zombie apocalypse, I'd find one of those huge regional distribution centers that supplies grocery stores. Plenty of food, it's a warehouse, so no windows and strong doors. Usually not very close to a large city. In a warehouse district with plenty of other goods to scavenge.
I think that was a plot-line in a post-apocalyptic (non-zombie) tv-show remake called survivors. As I recall, it was a mess of trouble because every survivor with a gun wanted to either steal from the place or take it over. Of course, that distribution center was in a city, and you might have fewer problems in a more rural area.