Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
If the phone is newly bought, but you have not yet 'originally entered' an email address, then you may just have a 'new' phone that isn't really new at all... that someone else had trouble with and returned.
One approach to this is, if you got it at a store, to simply take it back promptly (with the sales receipt in hand, and before the rather brief return-exchange period runs out) and ask for an exchange for another new phone of that type, since it is not working.
Does that sound like a practical approach? I have to ask, since I don't know your opinions and preferences, nor where, nor exactly how long ago, you bought the new phone in question.
(I regret that I am not able to offer Live Phone Call service at this time; However, your request is still open to other Experts in this category, and one of them may pick up on it at any time.)
In other words, you're saying that you forgot the email address you yourself originally put in?
There is no help for the situation, I fear, except to either
A. recover your recollection of the email address used
B. return the phone promptly to the vendor
C. get help from someone else (since I have run out of ideas on this case.)
To allow you a chance at (C), I have Opted Out, opening the case to other Experts.