Setup user account for the system. This is not the root account. Ubuntu made a safety precaution not to use root account by default. This is because root is the most powerful user in Linux/Unix system. Here you need to enter user's full name for the new user account. It doesn't matter if you just provide only the first name. But for the real system, put the user's full name because it will be used in the system email and other services that displays the user's real name.