iCloud activation problem
I have an iPhone 4s. Recently I upgraded firmware of this phone and then I can't active iCloud activation and can't use my phone. Cause, I have totally forgot my apple ID, password and all related things. But I have IMEI and Serial number and other information of this phone. How can I do now to recover it or use new apple ID?
iPhone 4S, iOS 9.3.5, Serial No: C39GJNR7DTDD