I have an apple id email/pw and an iCloud email/pw. They are not the same. I installed Maverick and now it is asking for pw for iCloud. I don't know it. Any ideas on how to reset or delete iCloud and start anew.

I have an apple id email/pw and an iCloud email/pw. They are not the same. It was working fine before installing Maverick and now it is asking for pw for iCloud. I don't know it. Any ideas on how to reset pw for icloud or delete iCloud and start anew? Under icloud preferences it list old email. At icloud preferences clicking on details, it shows the old email acct and an icloud email acct. Do I have two accounts floating around (3 apple devices in house)? If so how to delete one.