Hi. Thanks for the feedback.
The crafting mechanic is still incomplete. You can craft parts from resources by running into things like the workbenches, furnaces and rope machines and selecting the part you want to craft there.
The second part of the mechanic, however, isn't fully working. That's the part where you use those parts to create constructions that allows you to move between islands.
You can use the red 'carpets' to get from island to island, though, to eventually reach the top island.