Right below the MOTD window you have the Team (Race) Selection part:
There are four races in Netrek - Federation, Romulan, Klingon and Orion.
Each of the races has different ship pictures (though the ships have exactly the same power and weapons among the races).
In the race selection boxes you will see the number of players playing per race. If there is T-mode you will only be allowed to join one of the two main playing races. Otherwise you are allowed to select at least one of three teams.
In order to select team you should do one of two things:
If you want to quit - click on the clock box.
After death you will be presented the same team selection window. If you want to change your team or ship you should use the explanation above. However if you want to get back to same team in the same ship you can push the 'spacebar' and you are back.