NTA if the club was still open. She could go back inside to wait and call an Uber. If the club was closed, you could have at least driven her back home.

This is why I think it's stupid to pick people up on first dates anyway. Just meet there. The date could go bad, and then you are that person's ride. But, stupid as it is, that is what you two agreed to, so you were her ride for that night. If you are someone's ride, you can only abandon them before taking them home IF you know that they have another way home. Ubers are excellent for this, as long as the club was still open so she could wait safely inside. If not, then that makes Y T A.