Once your journal is created it will be available at either of the following links, replacing exampleusername with your username:
http://www.livejournal.com/users/exampleusername/
http://www.livejournal.com/~exampleusername/
If you have a Paid Account, it will be available at http://exampleusername.livejournal.com/ in addition to the previous URLs.
Maybe we could also add FAQ #131 to the bottom of this FAQ, as that information will be useful to new paid users looking to set up their accounts.