I forgot the AppleID password I set up 4 years ago now what?

I forgot the Apple ID I set up with 4 years ago . (Password)I can’t retrieve it because it wants to send me a code but it sends it to my phone number. My iPhone 13 pro does not have a SIM card as I received it from boost and it has no cellular service.

everything on this phone requires an Apple ID Password. I just paid $969.00 for my defective 13 pro. Apple techs worked on it twice and said it’s defective. The SIM card was bent and wouldn’t fit in the tray properly. My 14 days to return it to Boost expired and Apple wants me to take it back to the Apple store for a repair or replacement. The Apple store has to send it to Apple because the store won’t or can’t give me a working phone. I’m stuck. I want to delete iCloud because I have Google 1 and backed up to both. What happens if I delete the iCloud? Google has backed up the photos , documents ,contacts, what do I have to lose if I remove iCloud?