You start the game with a small tribe on the edge of a procedurally generated map. The first thing to do is designate a meeting area for your people to hang out. Once they make their way to the meeting area, they will decide on the best thing to do next. The first complaint is that their waterskins are empty. Humans can drink directly from a water source, but prefer to drink from their waterskins if possible.
We need to designate a water supply for our tribespeople. One thing to watch out for are mosquitoes in humid areas (the black dots on water). If you guide your people too close to a water source infested with mosquitoes, they risk catching malaria.
Once waterskins are filled, your people will complain about their dirty water. They can still drink it at the risk of catching typhoid (or a variety of other waterborne diseases). Water can be cleaned by bringing it to a fire. To make a fire we need wood, which can be obtained by a woodcutter chopping down trees. Fire also keeps the tribe warm during winter.
As a side note, currently I've reduced the number of professions to two - hunter and woodcutter. Both of these need specialized tools (hunter needs a knife and woodcutter needs an axe). All other activities can be performed by any tribe member.
Also, I've implemented a simple scheme where objects that are being carried/worn by a human show up on their body as a replica smaller version of what they look like when placed on the ground. I thought this was pretty cool, and saves the work required to draw two sprites for every wearable/carry-able item. Hope it doesn't look too bad.