So, you've downloaded and cracked the seal on a fresh copy of Unity. You've seen some examples of what other people have done with the game engine, and you've taken a whirlwind tour of the interface. You can clear out the Island Demo project by clicking on File | New Project in the menu. After choosing a folder for the new project, Unity may close down completely and start up again. Once it does, you're left staring at a 3D plane.
This plane stretches on forever in all directions seemingly infinitely to either side of you, ahead of you, behind you, straight down to the deepest depths, and straight up to the sky. It's time to build a game, right? But how do you start? Where do you start?