Do not become Mormon. Seriously. Fuck anyone that even jokes about joining that goddamn cult just so that they can be a prepper.
Preppers get a bad rep because there are a lot of far-right gravy seal types in it that think that with enough guns they can loot what they need, but there are a lot of more serious, sober people that recognize that the US is really bad at being ready for major disasters (like, say, a global pandemic?), and try to have as much of their own shit together as possible.
One really important tip: you will not survive a major disaster that causes a complete breakdown of society for an extended period of time unless you've built a community of people that are all working together.