Can't reset password on MacBook as it says 'There is an error connecting to the Apple id server'

Macbook is around 7 years old but I don't use it that often. Last time was around 10 months ago. I've tried to log in today but it doesn't accept the password (even though I wrote it down and I know it's right) and when I try to reset and enter my Apple ID info I an error message saying 'There is an error connecting to the Apple ID server.

I've checked the wifi and internet connections and it's all good. I also know that the Apple ID is correct as it works on my iPhone.

Can someone help please?