First off, have a paper list and a plan as to how you will execute your shopping chores. Kindly tell the god-fearing maga shoppers/transgressors to back away from you, counter-pray to our Lord of Light Satan, shop during hours reserved for the elderly or those with co-morbidities, wipe down your cart handles, do not take a child with you shopping, use the self-checkout instead of a cashier, use your own bags (I don't care what the store policy is), wear chemistry-type goggles and nitrile gloves, tell transgressors that you have COVID. Once you have left the store, squirt your canned goods and plastic packaging with alcohol and wipe them down, wipe down your hands outside your vehicle, remove your mask without touching the filter material(see YouTube for proper donning/doffing procedures, especially proper fitment of your mask), spray your mask with alcohol, put it on the dash in the sun for a bit, wipe your hands down again, remove your gloves and stow them in a ziploc to be disposed of, go home and change your clothes, especially leaving your shoes outside, leave cardboard boxed food in the sun or on the windowsill for a day or 2, produce and other things should be cooked and not eaten raw. Try going to a farmer's market outside to avoid closed spaces.
Once you have done these things, you have taken every possible precaution and minimized your risk as much as is possible. This is all stuff I do when I shop for my elder folks. I'm still on my first little bottle of 70% isopropyl alcohol after 3 months.
Hail Satan
-fixie