If you are looking for food then supermarkets are your bets bet for quantity, but they are hot zones. They are magnets for players. Food also spawns at residential buildings and farms. Industrial buildings like sheds, factories and warehouses spawn less food. If you have matches and a hunting knife (and find a pile of wood), you can kill livestock a, gut it and have lots of meat. Usually this can be done far away from populated areas so it is safer. Just rearrange your items so all the raw meat is in your primary before you light the fire. Then douse it as soon as you are done.