Before you do anything else, you must register your nickname. This must be done before you can register a channel as your own.
The command is:
/ns register *password* *email*
Where *password* is a password of your choice, and *email* is your email address.
Then, every time you log in, type:
/ns identify *password*
so the system recognizes your registered nickname. If you are using an IRC client that is able to perform commands on connect, you can put this command in your client's perform section so you don't have to do it by hand.