i don't remember the password i used to set up my apple icloud account

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

Use a web browser and reset Apple ID password , use the link Reset your password at iforgot.apple.com

Come to iPhone and sign in with Apple ID and its password , you must remember the three answers for respective questions , date of birth , rescue mail address and its password when account is set with secondary authentication account .

( a ) If you lose answers for Apple ID provide credit card details that was added in the account .

( b ) if you have lost Apple ID password provide invoice copy of Mac to apple support advisors .

( c ) Contact apple support , they will send a link on mail account , click on link after 24 hours to reset apple id password , however the link is valid for additional 3 hours .

( d ) Support pin is used by apple support advisors to verify the account when you know apple id password Generate a temporary Support PIN - Apple Support

See the article If you forgot your Apple ID password - Apple Support