First, stop , breathe and think. Second, Keep it simple, you do not need the latest and or newest or shiniest.
attached is a power point I made a few years ago about a 72 hour kit, Feel Free to adjust it.
Weight, as in no more than 25% of your total body weight
Pack: How to carry it and keep it from hurting yourself.
Items/Supplies Supplies are expendables like water, soap, food, medical supplies
Items are things like Ponchos, Bungee cords for the poncho, hammock if applicable.
Water, right after Air is a big deal, Lots of weigh at 8 lbs to the gallon approximately
Food, Mres are not necessarily your friend, They are costly, if you are going to buy and store long term food, there are other options
Shelter this is where things like the poncho come in. Tube tents are better than nothing, Heck you could use a few of the LARGE black trash/ garden bags for a short term, with either good fishing line or nylon twine if para or 550 cord is not available.
If you can not afford a multi tool, look into second hand shops. I have found a quart thermos, a US canteen cup, use that with a buddy burner and tada cooking and water purification if you have enough fuel for boiling water.
A tarp, preferable green or brown(no bright colors, if you want to not be seen), with a couple of blankets and sheet can make a decent bed roll with shelter. (Folks, We all should be aware this is a start, not a be all do all)
Training and practice, First aid, reading a map and using a compass, personally I have misgivings with GPS, too many parts, needs batteries/ electricity, is not always accurate and the signal system is subject to Government control, if a satellite channel gets shut off or encrypted, you have a nice shiny non brick brick.
In place of lighters for fire building, get a box of strike any where matches and wax, heck melting crayons will work, dip the heads and waterproofed matches,
seal with dryer lint laced with vaseline or dollar store petroleum jelly and you have a good fire starter.
add some tin foil,. fishing line, hooks and flies over time. include a can opener, salt, pepper, sugar in double or triple layered small ziplocs.
as to the pack, a few other considerations. Canuck and I both give reasons for internal frame or external frame packs. make up your own mind.
Load, balance and access, can you find it in the dark, no flashlight without dumping it all out on the ground?
feel free to personal email me if you want more information, but look around, just 'cause I know some stuff, does not mean I know all stuff.
Blueduck, Jerrydyoung and Brenda Nolen, along with Canuck and others are approachable. Feel free to reach out.
As to weapons, well we can give facts, it is up to you to stay legal.
Hope this helps. folks, feel free to comment. I know this is a short list, more of a general guide, if I overlooked something, it is not due to malice.