Shop local small businesses. Find and develop a relationship with local farms for meat and produce. Learn to grow heirloom veggies and harvest seeds. Slowly stock up on things you cant produce (tp, toiletries) by buying an extra each shopping trip. Learn and set up rainwater harvesting and purification. Buy young fruit trees that will produce in your area. If you are lucky enough to live in the right areas, learn to hunt, fish, shrimp & scallop harvest.
Have faith in the best outcome but prepare for the worst.