Beans and grains are a good place to start. But it's just as easy to store a variety as it is to just store beans and rice. That's important from a nutritional standpoint as well as to avoid appetite fatigue. Rather than try to simplify it down to the very least a person could get by on, why not work out a budget then buy what you can that fits within it.
First, you need to do a threat assessment. What do you see as the most likely threat to you personally? Make a list, 1 through 5. What is your condition? Single? Married? Children? What are your living arrangements? Do you own or rent? What type of vehicle do you drive? What is your geographical location? What is the political climate? Do you intend on bugging in or bugging out? You have to address these issues first. It will lead you to making the best decisions on what the bare minimum would be for your particular environment. TP
3. fire starting
4. firearm and ammo
6. portable shelter
7. hand tools
8. flash light
10. a bob
I won't go into specifics like you need rice, and beens, and oats, and a knife, and axe, striker fire started and glocks only because everything else is dumb and you don't want to be dumb now do you? Everything I wrote is covered more indepth on other parts of the site. It just covers the basics. If lightning strikes you house and insurance won't cover repairs for 2 weeks its not the end of the world, but those supplies will be pretty handy.
My essential bug out list:
katadyne pocket water filter
sleeping bag/w gortex bivy sac
22 lr rifle / with atleast 2k rounds
food/mre/ rice/ as much as you can carry
good knife fixed blade
hi cap pistol in atleast 9mm(atleast 100 rounds of ammo)
knowledge of the area/terrain /water sources/ maps/internally know north(not an item but knowledge prep)
socks atleast 5 pairs
pews perimeter defense ( will help you sleep knowing you have a perimeter alarm online)
backpacking stove that can run on white gas/ kerosene/ unleaded or anything in between
small shovel/ e-tool
rope or paracord and fishing line/hooks
in terms of bug in storage/ the sky is the limit and my list is long with much more food, armory, electricity, nbc gear, and some extra defensive items.
For a household bug in. these are good places to start.
Water and water filters for your sink like PUR 3 stage filtes
Powerd milk, if you use alot.
Small portable stove with a good stock of gas for cooking (In case of rolling blackouts)
Batterys for flashlights/lanterns/radios
Good pair of shoes
Soap and hand gel
Househlod items you use a lot like laundry soap.
Some good reading material.
Pets? Strock oum on dry and wet food.
If you have kids, make sure they have enough good clothes for about a year
One thing that I always bring with me is my Sony EReader and Solar Joos charger. As much as I love to prep and read about prepping, my mind can't hold everything I may need to know. I keep all of my survival manuals and misc survival info on my EReader so that if the occasion arises where I, say, need information on a certain plant that I do not recognize, I can look it up. The Solar Joos charges it and is very durable and water resistant.
Are they necessary, maybe not, but they could potentially make life much easier for me for the amount of space/weight they take up.