Forgot my Old Gmail account password

Hello,

Hello I was wondering how do I recover my password for an old Gmail account. I cannot remember what phone number I entered as the recovery number to the phone I was using. I have a new phone number and a different Gmail account I'm using now. My old account was also singed into a Google's photos account which I'm trying to recover so I can link the two accounts together by sharing my new Google's photos with my old Google's photos Gmail account. Plz tell me how I can recover my password to my old Gmail account