Some stuff we all already have, we can build toward further capabilities. I assume a stay in place scenario.

Skills trump things.

Physical and spiritual/psychological strength is imperative

• Water and rain catchment; Water purification (not just a filter, it needs to be purified)
• Food: start with grocery store canned - it is what you already eat (important!) and freeze dried is too expensive; start small and work up, don't try to buy 6 months of food all at once
• Medical and hygiene (personal and environmental): more people die of disease than direct combat in a war zone/grid down; get trained on your equipment. consider whether you want to add alternative medicine skills (esp herbalism)
• Power and heat: fuel, generator, solar battery, propane, seasoned wood; heater, camp stove,
• gardening: focus on stuff you eat and prioritize high caloric density and high micro nutrient plants. Learn to preserve your harvest.

THEN, as you are able

• Firearms as you are legally (?) allowed; recommend sidearm and long gun for each adult AND TRAINING!!! If you anticipate any hunting, consider an air rifle - not on the registry, cheap to own/operate/ train, good for marksmanship fundamentals training. good for mall game hunting (depends on your caliber)
• stack ammunition deep...recognize the need to training, possible hunting in addition to what you allocate for protection....training will be significant
• Repair parts: especially for home/shelter...nails, screws, Duct Tape, glue, plywood: also small engine parts and maintenance....POL, belts, machine screws, spark plugs, WD40; manual tools (both carpentry and mechanics)

THEN, when you are satisfied that you are reasonably sustainable,

• continue to add to skills and things
• start adding PMs. Silver is more easily used than gold, especially "junk"silver. Gold is a better sore of wealth, but silver is a better choice as a medium of exchange

don't get overwhelmed...prioritize and build a little at a time. Make training fun

Idk if a generator will save us like we think. It depends on the delivery of gas. And eats through a ton of it! We do have one in case it doesn't get that bad but we put in a wood burner the min Biden TOOK office. We have free access to 40 acres of downed wood at my brothers place. If gas is available, but in small amounts, we have chain saws, splitters and a truck. If not, we have axes, mauls and hatchets. We have cast iron to cook on and excess paper products such as cups, bowls, plates, plastic silverware. The idea is if we are down short term with no real water souce we could limit the clean up. We have two new rain barrels and a metal roof. I'm still working on a way to affordably filter water, but regardless, I can use this water for flushing and possibly washing clothes. Speaking of which, we have a 55 gallon drum and a new toilet plunger we hope will work for a wash tub and agitator. We have racks for drying clothing for winter and a clothes line for summer. Oh and we are working on cleaning up our root celler with a thought toward cold storage if we lose electricity. Although three sides are block against earth, one side opens into the basement which may not be cold enough. We have the normal battery lighting but having has many outages we know how short term batteries are. We tried solar yard lights and found them to be useles as the beam is not directed. So we have a few oil lamps and are storing oil. We garden and I can. Currently I have hundreds of fruits and veggies. I am experimenting with dehyderated foods and am learning how to use them. I still have to can meat and soups this winter. I have 25lbs of sugar and same of flour. We have about ten pounds each of a selection of beans. A friend has chickens. A crank weather radio with charge ports may or may not be important to facilitate communications. Add all that to stocking up on normal household goods and medical supplies jic supply lines are down. The hardest thing is come to gripes with you dont know what you are preparing or for how long. Days, weeks or years. It makes a difference.