I Can’t log into iTunes account
I have my correct Apple ID and password but when I want to sign in to iTunes store it says password or Apple ID is incorrect. I use the same Apple ID to login to my Apple account so I am sure there is nor problem with the account name and password. The window to sign up on iTunes store doesn't allow me to exit so I am not able to shut down or restart my Mac device. What should I do to fix this problem?
MacBook Air 13", macOS 10.13