Have you received emails from DreamHost telling you your account has been approved? You should also receive an email confirming your domain registration, assuming you registered a 'free' domain as part of the sign-up process.
I am not sure what you mean by this. How are you trying to add a new plan and why? If your account is approved, you should have an existing plan already under your account, there is no need to add another.
I suspect that all you need to do is wait for the confirmation email(s). Account approval times do vary quite a bit and it can take a few days, especially around this time of the year.
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