Apple ID's

Sorry, am a total dummy, mostly due to Covid, long Covid n long-haul Covid that I hv bn dealing with for past three yrs n hv not fully recovered. Don’t recall steps to check my web browser autofill entries, much less the Keychain, and other records, N worse yet hv not been able to pinpoint instructions on Apple Support. Hv wasted hours, weeks n or use Apple's support website to no avail. ihv tried Forgot service n nothing comes up. Problem with contacting Apple for help is that they take it for granted that everyone is a computer techie n that we know how to go from A to B, then C, n most r impatient with the older generation who r not as fast typing, or even understand some of the computer jargon. I wanted to find out the other Apple ID bcs I want to delete it so that noone will use it. Will thrink abt your suggestion to contact their Account Security team. Thanks for ur help anyway.