This my APPLE PHONE BUT I forgot my iCloud ID

Links for the above.

Apple ID - How to find your Apple         An iCloud e-mail address is an Apple ID.

Apple ID - Find

Enter your Apple (iCloud) ID and click Forgot Password.

Apple ID - Manage

Apple ID – Forgot Password

If you forgot your Apple ID - Apple Support

If you forgot your Apple ID password - Apple Support

There is no workaround for the security features of Activation Lock.

If you were the original purchaser and can prove it with

a receipt from Apple or Apple authorized iPhone retailer showing

the serial number of the iPhone, make a genius bar

reservation and bring in the receipt, iPad, and government

issued photo ID to Apple and they may assist in resolving the problem.

If the iPad was purchased used or there is no receipt, the AppleID and passcode must be recovered 

It is highly recommended that you make a Genius Bar Reservation to avoid delay at the Apple store

http://www.apple.com/retail/geniusbar/