Correct Password not working

Ok, thanks for verifying that. Somehow, then, the incorrect set of credentials are being sent when trying to use them with this Mac.

The few things that I think you can try would be:

• Boot up this Mac in Safe Mode. Try entering your Apple ID credentials.
• Boot up normally. This time, create a new user account. Try the credentials again.
• If neither of those work, it may be possible that the wrong credentials are still stored in this Mac's Keychain. You can either use the Keychain Access app to try to locate and correct it OR simply use the app to delete the current Keychain.

biofocus Said:

"Correct Password not working: Hey there, hope y'all surviving I'm having trouble signing into my Mac iCloud / Apple ID. [...]I've changed the password multiple times, and it still did not work on my MacBook only. How do I sign in please? What can I do?"

-------

Use the Login Screen:

Reset it using the login screen. You'd go through your Apple ID to perform this. Find out more here: If you Forgot your Mac Login Password - Apple Support

If you go to this Apple site, can you log in with your Apple ID credentials successfully there?

https://appleid.apple.com/#!&page=signin

I'm assuming that you are trying to log into your Apple ID to access iCloud services on this Mac, and have not been successful ... correct? Or is the issue with actually logging in with this Mac's user account?

Also, it would help if you can elaborate on what YouTube guide you are referring to as telling us that you "played around with terminal" doesn't provide us with much insight on what actually you did to get to this state.

You're very welcome! I'm glad you got it worked out.