Forgot my iCloud ID

iCloud uses your Apple ID and password. If you only have one Apple ID, it would be the same ID and password as you used to log into this forum. If you have another and have forgotten the ID or password, see the following:

If you forgot your Apple ID - Apple Support

or

If you forgot your Apple ID password - Apple Support

See if you can recover the ID/password.

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

Apple ID - Find              

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

Apple ID - Manage            

Apple ID – Forgot Password         

i lost my apple id but i have an imei number what to do

See: If you forgot your Apple ID  https://support.apple.com/en-us/HT201354  and

 If you forgot your Apple ID password https://support.apple.com/en-us/HT201487

You also can use Having trouble signing in/iForgot  https://iforgot.apple.com/password/verify/appleid 

And you'll undoubtedly need to see If you forgot the answers to your Apple ID security questions https://support.apple.com/en-us/HT201485

Given what you say, I don't think you will be able to answer your security questions satisfactorily. Being able to answer your security questions satisfactorily is critical. See Security and your Apple ID https://support.apple.com/en-us/HT201303

This document says “without proof of your identity via security questions and other carefully selected criteria, Apple Support can't help you reset a password or perform any other actions on your account.”

Thus, you will need to have an extenuating circumstance to move forward in solving your problem (e.g., have your original purchase receipt for your device new with its serial number on it). You say you don't have the needed receipt. What all of this means is the device will be useless to you.