First you need to connect to a server, and then you need to join a channel.

1. With Chatzilla open, type "/server irc.calindora.com" (without the quotes) and press enter.
2. Type "/join #eoff" to join the EoFF channel.
3. Type "/nick something" to change your nick to "something."
4. Type "/quit" to quit from IRC.

If you still have trouble, go to here: Chat - Eyes on Final Fantasy - Largest Final Fantasy Resource Online and somebody will be able to walk you through it.