What an awesome topic!
I would have wanted to hang out in North America, making spear heads like this:
Flint Knapped OBSIDIAN Spear Head
While sitting around the campfire, telling exaggerated stories about the hunt to the women and children gathered around.
By day I'd go hang out with the dudes, and sneak up on Mammoths..waiting until a moment where a strategic advantage is gained...then skillfully use a wooden sling to hurl the speak head at the mammoth at a rate of about sixty miles per hour.
Otherwise, hunt & gather...pick up and move on to more fertile grounds.
How would I choose my friends? They'd need to be skillful at shaping a good flint, be able to tell a good story...work well as a team player, using good instincts and strategy.
uh, wait a minute...that's almost exactly the way it works now.
no, that's not how i am now! i'm a a girl now! back then i'd be a boy and a very effective one indeed... i'd tell you a thing or two about hunters and gatherers and slings and arrows and such. specially about arrows. gawd were they overrated in the day. them were kids play, boy man i'd tell ya bout them for sures.