Okay. Take a deep breath, here we go:
Water: cheapest way is to get food-grade 55-gallon drums. Do a web search in your area. Local feed and seed stores keep some, too. Ask. Make sure no chemicals were stored in them; that they're food grade. In an emergency, you'd need 1 gal. per person, per day. So 55-gallon drum is good. Change your water out every year. Keep in cool, dark place with lid on. You can add a drop of bleach, or buy water purification tablets to have on hand.
Dry goods: Walton Seeds is about 4 months out on orders. Most popular one. Emergency Essentials, however, will get it to you in 1 week. Do some research so you don't do common food storage mistakes (like lack of variety; only grains, no cheese, etc; need to make palatable). They offer #10 cans and Superpails that have 02 obsorbers in them, plus they're vacuum-packed. This keeps out moisture and air (enemies of food). Store them in dry, cool place like basement. These can last for over 20 years.
Dry goods, cheaper ways: purchase a FoodSaver at Tuesday Morning (on sale now). These vacuum-pack food. If you want to do this to items like pastas, rice, etc., freeze them for 48 hours to kill any eggs (mealworms,...), let them dry out, and then vacuum-pack.
Flour/corn meal, etc.: If you want to do what you have instead of order from Emergency ESsentials (can get $$), put these items in your freezer for best storage.
CAN fruits/veges. Get your equipment.
Store up specially packed seeds from Emergency Essentials, too, for garden. Most seeds won't last due to moisture, elements. These are packaged specially. Put them in your refrigerator or freezer.