Join
Join is the command used to join a channel. It has the following format.
/join #chan
There a few cases where this command will not work. These cases are when the channel is invite only, a user is banned, or the channel has a channel key.
If the channel has a channel key, the following command must be used.
/join #chan channelKey
If the channel is invite only, use the following command and wait for another user to send an invite.
/knock #chan Message to channel ops.
If the user is banned, I am banned is hopefully helpful.