Simply click the "Register" button and complete the details.
What is a username?
A username is your alias on the site. Your username is what other members will see when they access your profile instead of your real name. Username should be in a Alpha-numeric form but at least 3 characters not exceeding 15 characters. Usernames must not have spaces or special characters such as (@--#%^&_*+). If your username is taken try putting some numbers before or after the name (example: 123John or John123).