Verification failed for Apple ID on new MacBook Air

I bought a new MacBook Air today in store - while setting it up it is not allowing me to sign into my Apple ID and keeps coming up with the message "Verification failed - an unknown error has occurred" even though the user and the password are both correct. Any tips on how to sign into my Apple ID?

[Re-Titled by Moderator]

Original Title: i bought a new macbook air and it will not let me sign into apple id