to craft press "e" while looking at the crafting table (you must be close, aka: don't go 1000 meters away)

when building i recommend you turn YSnapping on for floors and off for walls, windows, slopes etc.

when placing walls, windows, slopes etc. place them on top of floors instead of on the grass next to the floors.

if you have any questions about the game, please post them here. I am always happy to help.