To edit your profile, change to full-screen or exit the viewer, click on the three lines in the top right of the viewer. For more info on each UI tab along the bottom of the screen, please see the following:
To move your avatar around, you will need to use these keys:
W = Walk forward
A= Walk Left
S= Walk backward
D= Walk right
You can fly using R to start flying and to fly higher, and use C to land, or use Pg Up and Pg Down and WASD to change direction. You can also enable the option to ’Click to Walk’ under Settings.