Guns probably wouldn't be too useful in an apocalypse scenario. Durable tools, nonperishable foods and secure water storage is way more important. First and foremost, you would want to secure as much gasoline as possible to make sure all vehicles can run for the next few weeks. If any shelters can't provide anything for you, you would want to go home and start to turn off all useless devices and see about hooking up a generator.
As soon as the scenario starts, you would want to fill all sinks and bathtubs with water, then fill up any and all clean containers with water. I cannot stress how important clean drinking water is. You can ration food all you want, you cannot survive without optimal amounts of water.
Along with that, I'd probably hit the local good will, salvation army or town library for literary material. Any sort of technical skill books that could help me down the line.
