Welcome to DreamHost.
Firstly, has you account been approved yet? If so, you should have received an email giving you details of how to log-in to the admin panel and your FTP details etc.
DreamHost does not use cPanel, they use a custom written admin panel. You can log-in to the panel at the link below using the email address and password you specified during the sign-up process, however, if your account is still pending approval you will not be able to do a lot yet.
Edit: I must learn to type faster
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