How to get iCloud password forgotten

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 email address or phone number - Apple Support

or

If you forgot your Apple ID password - Apple Support

You have to sign out Apple ID from iPhone and delete the Apple ID address from the upcoming field , Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac - Apple Support

Click on forgot Apple ID or password ?