When the Attack comes, few people will be ready. First everyone will turn to the government for help, but the lack of order will leave plenty of openings for corruption on the highest level, thus leaving the government powerless in short time. Once the illusion of authority is gone, most people will panic. This will create widespread crime sprees in every major urban area, and few people will dare to venture outside after dark. Gangs of able-bodied citizens will then form to travel together and engage in combat. Those with medical knowledge will be valued highly and kept safe. After the initial food supply runs out, those in urban areas will begin to scavenge for food in the streets. The remainder of the manufactured foods will be horded and hidden away. Eventually the population density will drop greatly and the survivors will migrate into more rural areas. They will roam the land hunting wild animals and foraging for various plant foods. Once they have found a suitable area, they will setup a homestead with proper protections. These will be the people that will defeat them and repopulate the Earth.
Remember, there are only two kinds of people in this world. Those who have a zombie attack plan, and those who don't.