First and foremost…just walk.
Leave the car at home and walk to the store with a backpack. Carry it all back home on your back, prepare, cook and eat… then repeat.
I try and walk to work 2 or three times a week…15 miles round trip. Sure it takes me 4 hours to do it, but I try and work my schedule around that fact. All work and no play…
This is a vast area that many other people know a whole lot more about than I do. I will share what I can from a person level, but most likely share links to those that know what they are talking about.