It isn't easy to figure out how much food one should store for an entire year. I have said before that you should keep a food diary, to track how much your family eats to help you understand how much you really do go through, and give you a better idea of how much food you have to raise
Not everyone can raise their own food If you haven't yet LDS has a great resource. The Food Storage Calculator. You put in how many are in your family, click on calculate, then scroll past the ads to see the results This is just for suggestions, and is a great start so you are not hoarding and gathering blindly.