Invalid iCloud pw error? Wth man, what gives?

Hello everyone! I've been searching for resolutions and after failed attempts I come to you!

I have a 2014 11' MacBook Air - I am getting an error message where I am prompted to enter my iCloud pw. After entering it tho, it still errors. I've already signed out of the Apple Store- thinking I could just sign in again and magic would happen- but it gave me an even MORE bizarre error after the invalid pw: an unexpected error occurred while signing in. Failure. I've also tried disconnecting and reconnecting wifi...

Can anyone help? Your assistance is SO MUCH appreciated, you don't even know!

thank you