Hi, I have registered for a partner account and the account is activated, now if I try to create an org from using the Environment Hub, I keep getting an email message denying me an org.
I have tried 3 different email ids.

The message is as below - 

Sorry, we can't enroll you in a Salesforce Developer Edition account because the email address you entered is already in use. To sign up with a different email address, go to https://developer.salesforce.com/form/signup/freetrial.jsp (https://developer.salesforce.com/form/signup/freetrial.jsp" style="color:#0563c1; text-decoration:underline) .
 

I am currently taking the course Admin Trail Begginer: Getting Started With the Platform, when I proceed to sign up for a DE account I get the following message: "Sorry, we can't enroll you in a Salesforce Developer Edition account because the email address you entered is already in use. To sign up with a different email address, go to https://developer.salesforce.com/form/signup/freetrial.jsp ."

Does this mean I already have a Development Edition Account? If so where would I access it? 
Or should/can I sign up with any email adress fir a DE?