Generally speaking to register your nick on a network you use /msg nickserv register <password> <e-mail>
Replace <password> with the password of your choice.
Some networks use a case sensitive password, so be careful.
The e-mail address should be a valid address which you have access to, as many networks will send an e-mail to that address with a confirmation code and instructions on how to confirm your registration.
If the network does send a confirmation code, then you may need to confirm the registration before you can actually use the nick as a registered nick.
Whether you have a registered nick or not, you join a channel using the /join command.
Some channels may require you to have a registered nick, some may require a special key (which can only be gotten from someone that is in the channel).
If after reading this you still have trouble, then you should join the network help channel, which is usually #help, using the command
