To type with another person, you first pick any server from one of the available networks. Each network has servers in different cities all over the world. For the best performance pick a server that is close to you. Also, networks have wide varying content or topics of conversation on their channels. Some networks will carry the same topic as another network, but these channels do not connect to each other.
Some networks are safe for kids due to close monitoring of every channel.
Anothernet is one such example. The other networks do not bother censoring anything and are thus more prone to have many objectionable channels. After connecting to the server, you must pick a nickname. Then you can pick a channel to chat on. On some servers, this will kick you off, but there is an alternative to list the available channels.