You have to log into it before others do and fill it.
I switched servers to one that was listed as full to join a guild (which then completely vanished off the face of the internet not a day later) by logging in and switching worlds at a time no one should be playing games like 4 AM.
User will be infracted for this post.
Keep checking back and move when it isn’t full.
Trolls are like stray cats.
Feed them and they multiply.
Please do not feed them.
My first advise is to start your character on a different server. You can start playing and leveling. From the character select screen you can change your server at any time (process takes bout 5 minutes).
Like Shooopa said, the best change is on very odd times. Keep in mind that this server has a lot of players from the American-continents, but also from Australia and surrounding (according to http://www.gw2guilds.org/guilds/us/isle-of-janthir ). So my advise is to check somewhere round 6-7 am pacific time, the Australians will be statrting to go to bed, while it is still reasonable early on the east-coast, leaving only the African continent (EU players are mostly on EU-servers).
It can be that this server is so busy your not getting through anytime of the day/week. then the only solution is to ask to join you on a different server.
Arise, ye farmers of all nations
Arise, opressed of Tyria!