Pick up a
WaterBOB to make use of the water pressure before it's gone. It's cheap and is easy for anyone to hook up.
Best thing to focus on is dehydrated food with a long shelf life along with water filters. Your using this website so it's a given you already have gun's. If it's just a bolt action hunting rifle, I'd pick up an AR and buy a case or two of ammo to store away and use to practice from time to time.
If your staying at your place, buy a roll of barbwire & a big box of nails. Easier to crisscross the wire over your windows than to store wood and board them up. Also makes for good trip wire around the property for night prowlers, a few punji traps/sticks along with it and you'll feel a bit safer at night.
Pick up a cheap solar panel so you'll have a way to recharge things. I have a goalzero fordable model that fits in my go bag along with rechargeable batteries in AA & AAA for both flashlights and my Eotech 512.
Last but not least, medicine and bandages. Fish antibiotics are a must and really cheap....same stuff we use but for fish and unregulated. Band-aids, gauze, iodine, alcohol, & antibiotic ointment. Anything you can think of.....oh & vitamins....lol....would suck to try to survive off of beans w-rice and die of malnutrition.
Just remember, basics first and tactical later. The longer you can hold out inside your home the better. The majority of people won't have enough food to last 2 weeks & will be more tempted to snipe/kill a healthy person/family thinking they have the things that will feed their family. Better to stay out of sight rather than out in the open. Just keep in mind, behind every blade of grass there could be a gun pointed at you.
Like said before, always keep to yourself what you have. The hungrier a person gets the more violent they will become. Could be a long time neighbor or friend, they would think your set for the ice age and expect you to have enough to spare. Can't save the world, only you and your own.