One of my favs, Jessica (the gardening queen) talks about the wisdom of being prepared. You can start small, even if you live in an apartment or on a small city lot. This is a long video, but she has a lot of good suggestions. The things on her list:
Water: Store some water. Catch rain water, if you can. Have a way to purify water.
Dry goods/pantry goods: Beans, rice, wheat berries etc. are good pantry staples that can last a long time and will feed you and your family. Build a store of canned goods and stock your freezer.
Gardening: Learn. Start on a small scale. Have seeds. Build healthy soil: start a worm farm or compost.
First Aid: Have a supply of backup meds, if you can. Bandages, suture kits etc.
Hygiene supplies: Soap, rubbing alcohol, peroxide etc.
Pet supplies: Food and meds, if applicable
Clothing and shoes: Not a problem for adults, but it might be for children who are growing
Sewing kit: What you collect will be according to your needs and abilities. I always have a ton of supplies because I have always been a seamstress.
Other essentials: Batteries, matches, possibly oil lanterns. A charcoal/wood grill. A supply of wood?
Books: If you don’t have the internet, you will need how-to books, cookbooks etc.
The point is to do what you can for you in your situation; where you live, how much money you can spend, how much you already have. Your list won’t be the same as Jessica’s or mine. Just starting thinking about it, make your own list, and start/continue preparing.