As quietly as freaking possible.
After getting the heck out of dodge, only head to villages or small towns when you or your group are really short of supplies. There will always be more zomb's than ammo at least for the first year. However if they are the slow decay or halted decay type. Well, you are in for a long wait.
First, case your target. In this case a drugstore. If it looks intact or at least like no zomb's munched people in it, skirt the village and about a half mile away, set up some wind up Travel Alarm Clocks. Set em to go off an hour later. Skirt back to target. Wait for alarm to pull all the zombs out of their hidy holes.
For combat encounters I would use a PMR-30 .22 magnum. 30 rounds per clip with suppressor. Ammo is cheap. Taking down crawlers or shufflers would be the realm of Machete to the noggin. Since they are dead I don't have to worry too much of splatter but wearing a motocross mask and goggles with layers of clothing to frustrate gnawers. Wear a headlamp and have a tactical light on your gun. Use the Tactical light sparingly. Use a shoulder sling bag for storing your booty on your salvage run. Have a quick release on it if you need to bug out.
Always take your time and be on the watch for beathers. They will do you in faster than any Zomb.