When you first launch AltspaceVR, you will be given the username 'Guest' followed by a string of numbers. In order to customize your account, you'll need to click on the You tab in the menu. Enter a First Name (Display Name) your username and your email address. Once you customize your identity, you'll then be able to modify your avatar's appearance.
You will be sent a confirmation email. We highly recommend confirming your account via the link sent in the message. While this may not impede your ability to use AltspaceVR on your Gear VR, you will not be able to use the account on the PC or Mac client until you do so.