If you don't have land of your own, search startpage.com for "community garden" or "allotment garden" in your town or city and get on their waiting list. Usually takes 1-3 years because they are in such high demand.
Learn to grow food now when times are good and you'll always be a valuable member of your community no matter what happens.
A side benefit of community gardens is that you forge relationships with good, productive people in your community
The best crop to start with is potatoes. They are very easy to grow, yet extremely nutritious. If you have to, you can survive on just potatoes.
A good rule of thumb is to plant about 1/3 of your available land in potatoes in any one year, rotating where you grow potatoes each season. If you don't rotate, soil disease builds up in the soil.
If you want to hill your potatoes up like in this infographic, you will have to buy a medium or long season potato. I like "Nicola" or "German Butterball" for long season potato. A really good short season potato is Yukon Gold - done in 90-100 days.
Don't buy seed potatoes at the grocery store because they won't sprout properly. Buy them from a seen catalog or a potato farmer that doesn't use an anti-sprouting horomone.
Lazy as fuck and can't be bothered to water your garden? Me too. So make sure you mulch your plants heavily.
I shoot for at least 3 inches of leaf mulch, which I add a few times each year. It breaks down quickly, adding more soil to your garden which is extremely important. I add compost, then mulch 3-4 times per year, and RARELY water. If you mulch heavily enough it's not really necessary as long as you get some rainfall. Mulching literally means you only have to water 10-20% as much.
Make sure your 3-year crop rotation has 1 year of legumes in it. Legumes are special because they add nitrogen to the soil instead of depleting it. I like broad beans also called fava beans because they sprout super strong, are burly as fuck and can even grow through the winter as long as its not super cold. Here is a sample high-yield rotation
Potatoes->Garlic and Kale->Fava beans and peas
>>17603
day of the chipper soon my leafy friend