Finally, after stocking up on food supplies with varied use-by dates (don’t take just things with long useby dates, because you can save them for when everything else has gone bad), i would unblock the main door and we would all charge into the parking lot and attempt to kill the zeds while escaping to our vehicles. if possible, i would try to steal a nice big delivery truck, and get supplies and people without a vehicle in the back.

The broomhandle/kitchen knife spear idea is a good one, for keeping zombies away from you, and perhaps disabling their legs by slashing muscle and tendon. However, the amount of force it would take to drive a kitchen knife through the skull of an average human being would most likely destroy your spear.

I would suggest taking one of those canvas bags most grocery stores sell to avoid plastic bag waste, and putting one or more LARGE cans in it, like the ones they sell bulk tomato sauce in. Or even better, depending on the store, a pair of bricks. There you have a nice improvised mace. Messy, but effective and will be more difficult to break, and easier to remake once they do.

Keeping morale high will be difficult. I suggest using a reward system. Have people take turns scouting (in groups of at least three), and reward those that return. Give them alcohol, first pick from what they risked their lives getting, etc. Do the same with anyone making obvious effort to make your fort secure. Anyone who sits around whining and complaining will quickly learn that work equals reward.

Lastly, fill any empty containers with water as soon as they’re emptied. If and when the power goes out, the milk jugs and anything else perishable will go fast. Use what you can, then empty them out and fill them up, because you never know if the water will get shut off next or get contaminated somehow.

First, assess the threat level. Only two zombies coming through the front door means that a full scale attack hasn’t occurred yet, but is likely on the way. While I personally would help fend off those two Z’s, it’s not a bad idea to take a peek out the front doors. If the parking lot is full of zeds, then it’s time to eliminate any zeds inside and then lock the place down. If the parking lot is relatively empty, then give yourself 5 minutes to load what you can into your vehicle and get out.

Why only 5 minutes? Because you don’t know how many more are out there, or what situation the rest of the city is in. Taking any longer than just a few minutes could mean your window of escape-opportunity disappears, and then you’re left with no alternative but staying put.

Why get out at all? Many grocery stores are built as temporary bomb shelters, and have enough canned food for a long siege. However, it’s also the place any other survivors are going to be flocking to. It may sound cold-hearted, but being the one (percieved) as hoarding all the food is a good way to get killed. Not by zeds, but by your fellow survivors.

If lockdown is your only option, then use shelving, shopping carts, bags of cat litter, anything heavy to barricade ALL the exits. This includes things like small windows, air vents big enough for a small child to crawl through, everything. (You don’t know if animals can be infected, and a swarm of z-squirrels is NOT what you want waking you up some morning in your grocery-fort.) Make sure you have access to the roof, and spend some time AFTER you know you’re safe from break-ins building a rope ladder in case your fort becomes compromised, and for daytime excursions into other nearby stores for supplies.

Then it’s simply a waiting game. Eventually, you’ll either get the all-clear (unlikely), or your scouts will find a safer, easier to fortify place to live. Don’t demolish your barricades when you move out though, always have a place to run to if possible. Keep moving this way, old fort to new fort, safe location to safer location, until you’re out of the city and can find a good place out in the countryside to defend and start civilization anew.