Icloud is locked

Did you entered in Apple ID account ? as described above if iCloud storage is full see these articles https://support.apple.com/en-gb/HT204247

https://support.apple.com/kb/ph2655?locale=en_US

https://support.apple.com/kb/PH2643?locale=en_US

You can add a new rescue mail account , first create a new web mail account say with gmail services https://support.google.com/mail/answer/56256?hl=en

And see the section of rescue mail address in this article https://support.apple.com/en-in/HT201356

In the same Mac open a new tab ( press command and T keys ) sign in with your gmail account here in the web mail account you will see this code , come to the old tab in which apple id account is already opened , fill up the code in the fields and click on done to save 

Change Apple ID password using find my iPhone .

On your iPhone device , click on home . Scroll to next page > click on extras > you will find find my iPhone click on it , enter your Apple ID only , click on forgot Apple ID or password , click on next.

Reset options - choose how would you like to reset your password ( a )

Click on reset through mail and click on ok .

Then open your rescue mail with web browser ( server account ) , open mail > click on reset password > two fields will be shown .

( a ) new password …..

( b ) verify password ….

Enter the credentials , and click on reset password , the password is changed .