You get new parts to build with by finding new materials. So whatever resources are available to you, make sure to grab to find out what you can make with it. For mining, you'll need to build a smelter, for what can be built with the processed ore. Different trees drop different kinds of wood, so you need to chop them down to get the option to craft with the wood they drop.

That's one tip I wish I'd learned right away. Sample every resource. That's basically how you progress in this game.