Where do I start?

Hard to answer concisely; I maintain a 100% non-commercial and ad-free guide to level-headed prepping here, but not sure if you're interested in a longer read.

The basic advice I like to give people is not to worry about what's in the headlines; the headlines are, pretty much by definition, about events that are unusual. Some of the most likely risks you're facing are a lot more pedestrian: car accidents, trips, falls, accidental poisonings, insolvency due to run-of-the-mill recessions or unexpected bills. So, you know, a rainy-day fund, a fire extinguisher, and a defensive driving class should come before night vision gear.

Only once you have the likely personal risks covered, it makes sense to think about more widespread calamities - but don't start with supervolcanoes and space zombies. If you're in a region prone to wildfires, figure out a plan for when your suburb burns down. Same for hurricanes, earthquakes, flooding, etc. In most cases, the answer is not to run for the woods, but to have some money and basic supplies set aside, and a friend or a family member to crash with. Several days' or weeks' worth of food and water are good to have; bushcraft supplies and generators, probably less so.

You can certainly buy some bottled water and ready-to-eat non-perishable foods even on the tightest of budgets...

/r/preppers Thread