Ok most IRC's use /msg nickserv register password e-mail for example /msg nickserv your
mail@yourisp.com [email]yourpass12345@*@[/email]
Then once you have done this in performs add /msg nickserv identify password [email]yourpass12345@*@[/email] and tick the box so it performs on all networks.
P.S. some networks also use shortcuts like/ns,/cs or /hs etc
