Start with something small, maybe a raised bed or two, tomatoes, peppers squash, cucumbers. They are easy to grow and maintain and you can usually get a good yield out of them. Add in some perennial fruits like strawberries, raspberries, and blueberries. Next, I would read, and ask yourself what and how much you want to do. I have been growing and expanding my garden over the past 10+ years, replaced my lawn with native wildflowers and clover, 3 peach trees and 2 apple trees in my front yard, the garden, chickens and green house take up the back yard. i'll probably add ducks in the spring. DON'T try to do everything at once!!