You don't need an account. To change your name, press the tilde (~) key, and type "/name 'name' " where 'name' is the handle you wish to go by.
I'm assuming you've already downloaded the game, but if not, download the 1.1.0 release specific to your operating system from '
http://tremulous.net/files'.
Join a server by pressing 'Play' at the main screen, then press 'LAN' until it says 'Internet'. Press 'Get New List' and wait for the list of servers to populate.
Join one to play, but if you want to find your friends, and you know their in-game names, press 'Find Friend' from the server browser screen, input their name and press search.
