Up until plains, serious protection is not needed. A stake wall and sharp stakes suffice. Even a normal wooden hut will protect you from most enemies but Trolls. You have to lead those away from your base.

Once you hit the plains, things can get serious and you might need a moat around your base. Never had a horde attack so far, which I am surprised about, but you know, it might hit me tonight or tomorrow.

But that's the only attack that needs serious defenses. Trolls wreck everything, except when moats or earth walls are in their way. I don't like them, so I just kite them away and kill them.