Unknown Horizons begins in a boat in the middle of an archipelago. Your mission is to settle an island and start to exploit its resources. To do this, you need some basic infrastructure, which will cost you more resources.
To get resources, apart from exploiting your or nearby islands, you must negotiate with other players, or with the Indians, who inhabit these islands. However, if you decide it´s necessary, you can also attack them, and if you manage to conquer them, you keep any resources they have.
Careful management of resources and correct policy making will lead you to master the game. Give it a try!