Start with the basics. "Can we survive for 72 hours with nothing?" Shelter and warmth. Priority 1. Then expand to a week, then a couple of weeks then months. And if you are really lucky years. Take stock of what you use regularly in those time periods. Then decide what you can do without and what you can't. This way you can develope your personal short list. Most people's list will be a little different.
Now prepping for specific events can be done once the basics are met.
Now prepping for specific events can be done once the basics are met.