Fruits and vegetables are a great food source for after Z-Day. Because a garden is easily set up, and because it easily maintained, humans have been using farming to acquire fruits and vegetables since they started out on Earth. If your plan includes you surviving in your own house then a garden is easily creatable. In my opinion you should cut small holes in your attic/roof of your house, allowing sunlight to filter through, thus using your attic as a garden. Be careful with rain - it might mess with appliances, wood, etc in your house. If you worried about the puncture of your shelter then another option would be to set up a tube system to catch water using cisterns.
if you have waited a bit and have cleared substantial Zeds away from your home then you may be able to conduct a raid on the town. Home Depot is a very good first choice as at this point in time you should have a bit of foodstuffs but quite possibly not enough to barricade your shelter with. Places like Home Depot also carry materials that can be used to get your garden up and running. Remember to try and pick up vegetables like tomatoes and cherries (in seed form) because they produce renewable seeds that are easily to collect. It may be tough but vegetables are a great source of many of the nutrients that humans need and they're also very easily maintainable. While not a huge problem with good ventilation, the oxygen provided by the plants could be beneficial to you.
--Cylon1994 (edited by ysheth)
Dates(the fruit)

have been used for centuries by traders going across the sahara dessert and can last for months to years if stored correctly. very nutrient rich and has alot of protein (i think or vitamins). The pits are large so you can plant some easily.

Apples

nutrious and packed with vitamins, if you have an apple save the seads because if you want to settle down for the long run these babies will help feed you and your friends

Oranges

its almost the ditto of the above and citiris acid can be used to clean items and help your immune system.

Carrots
Good for the eyes, and make a great snack.

Potatoes
Great with a lot of other foods, Can be fried, stewed, mashed, etc. for a wide variety of meals.