I think I understand what you are saying and I'm going to address several things you posted.
1. You like to keep foods for 10-12 months that your family likes to eat and then you throw it out and start over. To be honest I'm not sure what foods you keep in your pantry, but most canned, jarred or tinned foods stay good well beyond their expiration dates, so you don't need to worry about it going bad and making your family sick.
The easiest way that I have found to build up your food supply is to make a menu of foods that you and your family like to eat, then when you go to the market just pick up a little extra that can be put on your shelves. For example, if your child likes canned ravioli, instead of buying 1 can, buy 3 each time you go to the store. Just buy extra to have on hand, that way it's not a huge expense all at once.
2. You are right in the fact that you need to have seed enough to plant a garden. If you already know what grows well in your climate or if you have a garden already, then try to find heirloom varieties of those vegetables and fruits. With the heirloom produce, you can keep seed from your harvest to grow during the next season.
3. Like you, I do not plan to leave my home unless I absolutely must. Dehydrated foods are lighter to carry and you can pack more food into small spaces with it. However with dehydrated foods, you must have enough water to rehydrate the food to eat. Which means storing extra water in addition to your drinking water, unless you have an adequate water source you can depend on.
4. It's good that you and your wife both cook. Now is the time to start familiarizing your family to longer term storage foods such as oats, rice, and beans to name a few. Learning many ways to cook the same ingredients will come in useful to battle something called appetite fatigue, which is when even though you have food, you choose not to eat because it's something you're tired of. You see this a lot in the elderly who just seem to nibble at their food.
5. Are you asking about building shelters, hunting, and defense tactics? There are plenty of people on this forum that can help you out as well as suggest other sources of information.
I don't know if you and your family go camping, but that is a good starting point.