Okay, the first thing you need, if you are a caveman in a small tribe of cavemen, is a source of fresh water.
'Cause you can go for a good long while without everything else, but you won't last too long without any water.
Unless you are a caveman that lives in a cold and snowy place, 'cause then the first thing you need to find yourself is some pants, so you don't freeze your nuts off.
On the bright side, there's a lot of water laying around on the ground up there in the snowy places, so you don't really have to worry about water so much.
So for the caveman from the warm place, pants are optional, but water is an issue.
And for the caveman from the cold place, water is easy to find, but pants are a serious issue.
After that, you need food, but the search for fresh water and a good pair of pants tends to move you toward an area where food sources are gonna be concentrating naturally, y'know, 'cause all the other plants and animals need water, too, and in a place where they can eat snow, animals are the things that you are gonna make into pants, with food as waste product.
And the animals that are gonna wanna eat you (and turn you into a pair of furry nut-coverers, through digestion, which is nature's Pants Factory) are gonna be there, too, y'know?
And maybe the animals don't really wanna eat you, but they sure as hell don't wanna share their berries and coconuts and pants-providing animals and shit.
So the fights for food start at the river, or they start over a good pair of pants in an area where pants-worthy animals are plentiful, depending on where you come from, and that's how you learn not to be such a newb at fighting.
Anyways once the optional pants and water issues are taken care of, then you can start looking for places where you can get better food.
Like berry patches and places where animals that are easy to catch hang out and shit.
Y'know, hunting and gathering.
And once you find those places, you make a map of them in your head.
And you walk between 'em.
And you won't wanna share 'em with all the other animals, like the birds that wanna eat all yer raspberries, and the wolves that wanna eat those easy-to-catch dodo birds and shit, y'know?
And so you start driving the animals away, by waving your arms and making crazy noises and shit, which is a total pain in the ass, 'cause you have to do it in person.
And that's basically the beginning of farming.
Y'know, yer tending to those areas where plants and animals you want can be found.
If yer smart, you might realize that weeding and fertilizing the berry bushes help more berry bushes grow.
And that feeding the dodo birds and protecting them from wolves makes for more tasty dodo birds to eat.
So that's the beginning of domesticating plants and animals, and military defense systems that protect your berry bushes from birds and shit, starting with fences and scarecrows and stuff.
Of course, the better your area for hunting and gathering, the more its gonna attract other hungry cavemen.
And so you are gonna have to fight with them to protect your area, 'cause now that you ain't a wandering nomad, now that you got yerself a good berry patch, now that you put all that work into it, making a map of the berry patches in the area, and protecting it from birds and weeding it and shit, you don't wanna just leave it and start all over some place else so you can avoid dangerous confrontations and let these other stupid cavemen have it.
Same thing with hunting grounds, if yer a caveman from a cold place, y'know, you don't wanna just let these guys take all the pants-n-meat-providing animals that you spent all that time protecting from wolf attacks in the middle of the night.
Unless the new cavemen that show up are sexy cavewomen, who are better looking than the women in your tribe, 'cause then you'll share, although it'll probably break your heart a little bit to give them a pair of pants if yer one of those cavemen from the cold place heh.
Or, y'know, if yer a cavewoman from a warm place, you'll prolly share your berries with a sexy looking caveman with a nice butt.
But once again, the caveman from the snowy place is sorta screwed, 'cause his furry pants might make his butt look fat, even though it isn't, and he won't be getting any berries.
But maybe you can make up for it with a sexy voice like Sean Connery or something.