So what you're essentially doing is making your own garden of eden thing where god makes a man and woman and they have kids but yours might be that god made 5 couples, either way same deal. How do they fend for themselves and then provide enough for more than just getting by and eventually spread out and and form a culture and civilization? There's no one answer and that's the sort of thing that writers, philosophers, and anthropologists do. My short story/theory would be that they hunted/gathered for a few generations and, evolution being what it is, someone was born smarter or more clever than the others and came up with some new ideas on how to do things. This person could have either been exalted or exiled depending on how conservative the "elders" were. This person took the spouse/family and moved over the hill into the next valley (or a few valleys over) and did their thing. They could have died or they could have flourished, either way makes for more story and starts the spreading out process. Some families have lots of kids and therefore need more food and space so they have to venture further out to find food and maybe they find a better place. Maybe they find the clan of the exiled dudes and are kidnapped forcing the others to go looking for them and this starts a fight. At any rate as the populace grows you need more and more things starting with more food then fancier bones to hang around your neck and fancier sticks with which to beat each other up with then fancier homes to provide for defense against those with bigger sticks and if you can't get a fancier house you move further away from the trouble-makers but some will stay because they think they're tough or something and others will try to be trickier and others will try to outsmart everyone and some just take the power. Those with power tend to stay put and those without power tend to move away from the "jerks". Those staying put see their way as being the best way and so they become stale and more conservative in their thinking while the "wimps" that moved away tend to be more open to new ideas if it will help them beat the other guys. So now we have the beginnings of different cultures among tribes (they could also evolve into separate races) and also early hierarchies or politics. As soon as one person crushes up some berries and rubs it on his face and wins a battle he gets superstitious and this starts mysticism or religion or magic. Some dudes are better at fishing and some dudes are better at building huts and this starts specialization among people. The more things you have the more other people are going to have different opinions and they either leave to make new clans or they stay and try to figure out how to get on top. The old "you've got something that I want but I can't beat you up" leads to crime. This is envy, and really, it's the seven deadly sins that drive folks apart but new ideas and change play a decent-sized part as well even though those willful enough to move away and test their ideas are still doing it because of pride. Some people are born deformed and so are shunned but they're otherwise as smart or funny as anyone else but if they are forced to leave they can start up a new culture (provided they can get a spouse) in which such prejudices are not tolerated...but maybe they shun the pretty faces or the slow-witted (shrug). Anyway, once you have enough people to assert some sort of dominance over an area that area becomes off-limits to others and you now have a kingdom (or some other type of geo-spatial-political name). Once those bone necklaces start having fancy rocks in them or shiny metals you start getting a currency - this can come at any part in the story. Maybe the folks never get that far before they get a barter system - maybe the fisher dude says he'll catch some fish if the other dude builds him a hut but, more often than not, it has something to do with material possessions. "Nice necklace there, I'll trade you my fur boots for it". Now we have trade, trade usually leads to an interchange of ideas between peoples, whether they be in the same village or different kingdoms. This interchange of ideas opens new avenues of thought and the most clever and smartest excel and this leads to education. One dude banging a stick on a hollow log makes a sound and others bang rocks and we get music. Just put your brain to work on what's important to your story and think your way through it. This is my short story, everyone will have their own ideas as well...and I shun them heh heh