I prepare for it by living in NYC
.
Less people own cars here or even know how to drive than any other place in the USA.
A food shopping run for me can readily be a 5 mile walk and I shop about 2 or 3 times a week. I do 2 miles to get to the furthest shop, 2 miles back, and a mile or so of walking in and out of shops. Now that stores like Whole Food have come to Manhattan I no longer have to stop at separate greengrocers, the butcher shop and fishmonger's but I still do (I enjoy picking what I eat w/o it being covered in plastic and Styrofoam) except when holiday food shopping when I walk down and cab back.
A good way for a novice to start is to purposely walk up and down stairs in a house. Top floor to basement to wash clothing; be sure to bring them back upstairs the same day
and put them away. This accomplishes a few goals: organising the house and getting walking time in.
Work in an office with an elevator? Get off the ride one or two floors before your destination and walk up. Walking down counts too as it help to keep your balance and the knees are more "lubricated'.
Have a garden? Pull weeds every morning before the sun is high in the sky. Limbers up the overall body.
Take a walk in a local park or nature preserve and enjoy your surroundings and clear your mind at the sametime.
My life philosophy is to treat my body with more respect than the car I don't own. I can replace a car but a body is more expensive to repair and should last longer.