I've been using FH since 2011, so I honestly can't even remember which map was my first. One of the earliest ones I do remember making, though, was a really small island map with a cave covered by a waterfall. Then a put a bunch of caves inside the cave, for some reason. I also vaguely remember making a completely flat map, and I just covered the edges in trees.... perhaps that one was my first.
My old maps were really bad.