That's why you have reserves. Canned food (either purchased or from pervious years) dry goods, that kind of thing.

As for the animals, well chickens are pretty damn easy. They self replicate too haha. Chicken feed and shelter (not that mine ever use the coop I spent a ton of money and time on) and then predator protection. That's probably your biggest concern. Hawks, coyotes, foxes, raccoons, stray dogs all are a problem. IMO the most effective defense is an excellent flock guardian. I have large fenced area that the chickens stay in (mostly) and the dog stays out there. Anatolians are the best, but they aren't for novice dog owners. A great Pyrenees is also a good choice, but they require lots more grooming. You can also look into a mix. There's a few other breeds also but they aren't as common.

Goats are hardy but Hella hard to keep fenced. Like extremely hard. Don't get them unless your neighbors are cool with waking up to a goat occasionally.

If you want a cow, look into the mini versions. They produce more meat/milk per pound of feed than the full size version. Bonus, lots of people like them as pets so you can sell offspring for a good price.

I have no experience with sheep, other than that they are assholes and a pain in an ass to handle lol. If you want wool type stuff, I would recommend an alpac. Never had one, but they are on my list when I by a bigger farm.