It's a legit method. Mylar bags in food grade buckets with desiccant O2 absorbers and gamma seal lids. Vacuum sealing works pretty well too. But both those are mid-term solutions. It's almost always cheaper to buy your own supplies rather than ready made kits. Throw salt/pepper/vitamins in each bucket.

I have a two-burner Coleman stove, the full-size one that takes BBQ propane bottles, and a ton of fuel. Plus a set of cast-iron kettles/dutch ovens and a tripod for going cauldron mode over an open fire. Get a BBQ like the Egg that you can just build a fire inside for when fuel runs out. Learn how to manage a wood fire if you don't already know and choose to live where wood is available.

Get a grayl canister filter and some lifestraws plus one of their gravity bag filters. Iodine tablets.

For sleeping dry and warm, get a zero-degree sleeping bag (I like my KSB-0), a decent ground pad like the compact Sea-to-Summit models, and a decent tent, I have an old REI Quarter Dome, not sure what's out there now.

Buy wool clothes and blankets. Good wool socks and long underwear are a game changer. Get a real set of leather boots (Nicks) and a set of insulated pack boots if you live where it snows (Hoffmans are the best). Own a set of real rain gear. Filson tin pants are legendary and the heaviest tier carhartt PCV coats are impervious.

Find a paramedic and get whatever trauma kit he recommends. Supplement with suture kits, chest seals, chest darts, H-bandages, and some burn sheets for a start, plus any IV supplies. Read up on medicinal plants and natural medicine. You can make lots of excellent remedies and wound treatments out of a decent garden.

Get books on any survival topic you aren't already familiar with. Doesn't matter how well-prepared any of us are we're all going to be struggling hard in some area if/when things fall apart. Don't get overwhelmed, you can never be 100% perfectly prepared and you certainly can't get there overnight. Just don't do nothing.

Mylar works ok. I use a vacuum sealer and put a desiccant bag in each one. then pack the bucket full and put some desiccant bags in it and seal it.

Your asking way to much for one post, look up forums for this. Yes mylar is good but you need to add o2 absorbers. Dont buy pinto beans and expect them to last. They just get hard as hell. Precooked dried beans are the way to go. Less cooking time. Your way behind the curve, your gonna have to spend alot more if you can get it.

On the west coast, Winco supermarkets used to stock these, and desiccant packets.

Why would you waste Mylar on food when it could be used for preserving comic books?