My question ban was revoked. I don't know how or why. Can anyone tell me why? Because I didn't answer any questions, only one of my questions was upvoted, nothing else.
Also, does this mean that I won't get a question ban again?
If your question ban was revoked with a single upvote, that means you were very near the ban threshold. The upvote may have taken you over the threshold, but it can't be by far, and yes you could be question banned again.
I'd advise you to follow the suggestions given to you in the ban link, improve your existing posts and provide some good answers. Hopefully you won't get question banned again in the future, it's completely up to you.