To move in build mode, grab with your middle finger, and pull yourself around the world. When grabbing with both hands, moving them closer will scale your avatar larger. While moving your hands apart will make you smaller. The larger you are, the further you will move in the world. You can rotate yourself by grabbing with both hands and rotating the world around you.
Important
Make sure to use your middle finger for moving, grabbing with your index finger will be used for something else later.
It’s recommended to start moving around slowly as new users may experience discomfort.