Sounds to me like the message is quite self-explanatory. The nick registration service is waiting for a confirmation code that it has sent to you via the e-mail address that you provided. Until you get that e-mail and follow the instructions included, your nick isn't fully registered. This is a common method of ensuring that people don't register a nick and not have a valid e-mail address associated with it. The valid e-mail address is normally used to relay your password back to you in case you forget it (after providing some other form of identification to show that you are entitled to that information)