it depends, if it's an apocalypse having to do with an impact event (meteor, asteroid, comet) then I wouldn't do stuff. If it is a pandemic of some sort (zombies, virus, fungus, etc) I would gather up on supplies and weapons, probably go out on my own with a trustworthy friend or someone that isn't infected.
If it's some sort of fallout, I honestly don't know what I would do. I probably would try to seek out a shelter of some sort, or something like that.