I made a lot of weird looking and ugly shacks when I first started playing. But your workbench, your bed, the campfire smoke, and the local wildlife will tell you if you are doing it wrong. Don't worry about it looking good until you have more practice. If it beaks, you don't lose any material and you can try again.

Beams are only important if you are using them to support something taller than your walls can handle, or for holding up a large roof in the middle. Core wood and iron wood beams that you get later will let you build taller. Otherwise, they're just for decoration, or filling in a gap, or for preventing clumsy vikings from stepping in the fire.