@Dirty_habiTIn the winter on mountains I just melt snow, or cook it on the jet boil if we're waiting for a long time. Typically if I am climbing I just pack snow in a water bottle and throw it in my jacket to melt. Otherwise it's a LifeStraw Water filter or Gravity Bag (depending how much is needed) or a MSR MiniWorks. Also the Sawyer Squeeze is good too. Iodine Tablets are always good to have with you too just in case.
For back packing food prior to my allergies I would pack a lot of Granola Bars, Cliff Bars, Trail Mix type stuff. But for camping food at actual camp man there's a plethora of ideas. Instant Potatoes/Rice are great and lightweight options and heavy/filling. Ramen/Cup of Noodles. Dehydrated fruits and meats for multidays. Tuna/Chicken packets are great and cheap. I used to get MRE's or those packaged meals at REI or Sport Stores but they're hella expensive and you can pretty much make your own.
When I go on a trek I always look to ensure there is a water way atleast somewhere. I hate carrying tons of water and it's heavy. Many trails these days have youtube reviews and you can get an idea at what mile point they are and what seasons theyre running. Atleast for the ones I have looked at over the last couple years. For instance I am looking into the Ozark National Forest and the Ouachita National Forest and there happens to be alot of information on youtube, reddit and forums for it.
Someone else maybe able to piggy back off this with better knowledge or articulation.
Alot of cheap gear can be found on SteepandCheap and SierraTradingPost, I also use Poshmark and Ebay. I get name brand gear for 75% off and wont ever pay fullprice for it.
My typical Winter/Spring/Fall pack
Black Diamond Hiking Poles
Black Diamond Ice Axe
Kahtoolah K10 Crampons
Lifeline Snow Shovel
Black Diamond Helmet (depending on what I am doing)
Black Diamond Headlamp
2x Plastic Nalgene Bottles, or Hydroflask, or other bottle depending
USGI Military Poncho or USGI Goretex Liner
Tent (depending on where we're staying)
USGI Military Poncho Liner
Mountain Hardwear Lamina Z Torch Sleeping Bag or USGI Military Sleep System (depending)
Pocket Knife & Belt Knife (typically Kershaw Cryo 2 & Ontario 499 Knife)
Hatchet (Typically a Schrade SCAXE2)
Survival Tin (space blanket, waterproof matches, etc)
Trash Bag(s)
Goretex Jacket/Rain Jacket (depending)
Down/Insulated Puffy Jacket
Fleece Base Layer
Polypro Pants and Shirt
Extra Socks & Underwear
Streamlight Pen Flashlight
Firestick of some sort
I am sure there is some more stuff but that's the basics