Okay, so you chop down the tree to get the wood. You get the wood to make a workbench. You use the workbench to make tools. You use the tools to build a shelter before it turns dark and the monsters come. And that's just day one. After that I always set up a wheatfarm for a first selfsustaining foodsource, and hunt for whooly sheep so I can build a bed and sleep through the nights.
Ultimately you have an infinitely large map to explore and build stuff in, and manipulate, down to the cubic unit. It has this 'the world is your oister' appeal that made it a huge cult indie hit.