You must use an active phone # to use iMessage on an iPhone. Beyond that, you can choose whether you attach an Apple ID to it or not, and even choose if you would like to initiate your iMessage conversations through your Apple ID or your phone #. Your desire to have neither is simply not a possibility. Pure and simple.
Please note: users that own a non-cellular device such as an iPad, iPod Touch, or Mac can activate iMessage without the use of a phone number by design. To provide cellular service is not their default nature.
""IN "send and receive" section, there is only my apple id not my number.
BUt someone who had only my number not apple id could send me imessage and saw blue my number in contact list.""
There ARE instances where iMessage becomes untethered from your phone number or fails to activate with it. This is not intended and the troubleshooting for such instances can be found in the following article.
If you get an error when trying to activate iMessage or FaceTime - Apple Support
You may also deregister your phone # from iMessage by going here - https://selfsolve.apple.com/deregister-imessage