I cannot emphasize to people enough the importance of getting started.
All it would take is buying an extra five pounds of rice or beans a week, and putting it in a safe/secure area.
If you can do more, that’s even better.
Good suggestions from all. And don’t forget producing your own food. A small raised bed garden or even a small aquaponices setup can supplement your needs. Backyard chickens can also provide a continual protein supply. Also of value would be first aid supplies and some knowledge in folk remedies. Every little bit helps.
You’re assuming that there will be clean water.