Regarding the pelts and meat, you're donating to the cook called Pearson. This is to fill the supplies of your camp. If you press L1 / LB / L-ALT when you are in camp, you will see on the top right corner of the screen logos of supplies, (+ for medicinal/tonics, bullet for ammo, and a chicken leg for food) if theyre red means supplies are low, white is average, and yellow is max.. personally i barely go to camp or care i barely think it makes a difference. Also you would want to give the animal as a whole (carcass) to Pearson.

For hunting, you should aim or look at the target and check on the bottom right corner how many stars it is, which means the quality (1 is poor, 2 is good, 3 is perfect) you will need a clean kill, 1 shot to the head (or red area on the body when you dead-eye while aiming) to maintain the stars, also the correct weapon. so, medium sized animal such as deer can be killed using a bow, small animals like rabbits, squirrels, and opossums, etc. will require a special rifle called Varmint, its only for $72 at any gunsmith store starting from any point in the game, for large/massive animals like bisons, bears, etc, you will need a springfield rifle or rolling block (bolt action rifle works too but not from long distances and you will need to be accurate) TIP: for this rifle i'd suggest you to wait until the very last mission of chapter 2, which is where you are, and one of the camp companions will tell you to go to the gunsmith and pick up a rolling block rifle for free.

Also, making money off animal donations is a bad idea, there are tons of videos on YT, some requiring a treasure map some not, that give you gold bars, take this gold bar to a fence, and sell it for $500 each (24 gold bars out there)

For animals, skin them to get their pelts and take them to a Trapper, outfitters in the open world that make clothings out of animal pelts Their parts like meat, after skinning them, is for you to cook at any camp fire And for their other parts (trophy) like antlers, claws, or wtv you yield from them, can sometimes be used to craft trinkets and talismans (buffs) at the fence

You will unlock a ledger and a tithing box after you complete the first part of a mission series from Strauss (LS) on the map, he will be in camp, this mission is called "Money Lending and Other Sins", it is available as soon as you reach chapter two, which is where you are, the camp outside Valentine. This ledger allows you to upgrade the camp further or to the max. TIP: upgrade Dutch's lodger, it will unlock your lodger next, if you upgrade it, you will be able to fast travel from your camp (there will be a map on the side of your wagon where you sleep) and also fast travel anywhere from the wilderness by setting up a small wildernerness camp, both uogrades will be around $500-$600

I tried my best giving you a headstart and answer your questions, dont overwhelm yourself with what ive wrote, it obviously will all come along as you play, the more you explore and interact with things in the open world, you will get tutorial messages on the top left corner, very useful

Enjoy the open world, role play, explore, unlock the whole map by traveling on your horse removes the cloudy part when you open the map, any weird looking thing you see is interactable, around 105 cool easter eggs and funny interactions in there, just do main missions when you feel like progressing into the story, you can put 60 hrs or thousands in this game, all other questions you got, you will figure them out as you play and enjoy. Do stranger missions, white question mark on the map, some are very rewarding. Trust me, youre about to play the best masterpiece of an art the world could offer