You only need to do that if you want to view it on the web.
From https://panel.dreamhost.com/kbase/index.cgi?area=362 :
Use the FTP client to connect to yourdomain.com (if your domain hasn’t been transferred to us yet, you can connect temporarily to your machine name as reported to you in the welcome email… something like machine.dreamhost.com), and let it automatically detect the host type. To connect, use your username and password that you chose for your account. If your ftp client asks for the “initial remote host directory”, you can just leave that blank.