How to find icloud ID to activate my iphone
Do you mean an Apple ID, right? There are one method that will be helpful to you. 


Find a Forgotten Apple ID by Email.


It is incredibly helpful if you switched email accounts at some point in time and that’s what has caused the login problem. This can be done with any web browser in iOS, OS X, or Windows:


Open the web browser of choice and go to this Apple iForgot page
Enter the first and last name associated with the Apple ID, your current email address, and any and all prior email addresses to start the reset process
Answer the security questions to complete the reset process