You can sign in as a Guest, click the guest icon beside the Facebook and Twitter icon, and change your name from Guest123 to your name or a nickname.
Don't click on 'Me', instead, continue to scroll down until you see the Facebook and Twitter icon, as the Guest icon is located to the right of it.
Remember not to add your full name.
Remember that this is a public website so all information displayed on the chat table will be viewable by others, so be careful about what and how you write.
Apart from that, enjoy typing.