First off, during stage one of infection outbreak, the key thing to do is to know where you stand. Is your location well fortified? Is it full with supplies? Who do you have with you? What to do after situation is assesed.
First, My house is surrounded on all sides by fences. So I know that I'll be safe while I sleep. Second I'll board up my windows just in case of a perimeter breach. After preparation is complete, I'll gather with me 4 of my aquantances. You always travel in pairs. W'ell asses the situation of the town. If the infection is too severe, we know that there will be no chance of servival, and leave the city. Otherwise, we stay in our fortress,(which will be stalked to the brim with ammo) and form hunting parties. We eventually save the town from outbreak. If you want more detail, I can provide it. just email me.