IF you are using this map after the Apocalypse, you are already neck deep in the brown stuff.
And yes, I absolutely avoid Walmart after dark, never go there on weekends, and when possible on days ending in “y” I drive right past it, but sometimes there it is and there I am, and it works out ok.
The only ammo my (two) nearby Walmarts don’t carry that I want are M2 Ball (Garand) and .303 British (Enfield). They normally have 9 mm, .22, .22WMR, .30 Carbine, and 7.62×39 on the shelf. They also always have 12 and 20 Ga. shotshells available. Major advantage, I don’t have to sign anything or wait for my purchase to ship from Lord-knows-where.
As far as other needs are concerned, I have at least 3 months’s worth of food in the pantry, and keep it that way with semi-monthly stops at Sam’s and Walmart.
One hour notice; fill water containers.
One day notice; store for whatever, gas, fill water.
Any longer, I might consider relocating inland.
Wal-Mart has good prices on ammo, but it is seldom seen around these high-falutin’ Google-Peninsula parts. All the zombies seem to work at Google where they stagger out into traffic looking at a little thing in their palm, talking to the wind.