Depends if your server has services. Usually most do, but on occasion some don't. I'd either try to type
/chanserv help or
/msg chanserv help and see if anything displays in your status window. If it goes on about services, the command you want is (Soemthing like):
/chanserv register <channel> <password> [description]
You usually have to be an operator on the channel when typing that command. Again, if /msg chanserv works on the help command, use that instead of /chanserv. Additionally, replace <channel> with your channel, <password> with your password, and the description is also usually optional. For an example, if I wanted to register #kingtomato with the password "secret", i'd use:
/chanserv register #kingtomato secet This is a channel description
Once registered, you then use
/chanserv identify <channel> <password> to identify as the owner of the channel.
If these don't seem to wrok, try joining #help, #opers, or #services on your network. There is usually an operator there whom can assist you.