Earlier on when I asked a question, as I am 14, I asked it in the school breaktime, but someone thought it funny to add 'porn' onto it and press post question, creating a tag called 'hackingporn' and I was wondering if it is possible to remove this tag.
Just remove the tag from the question. Tags which aren't used by any questions just disappear on their own after a short while. In this case, though, since the tag content is questionable, a staff member might come along and accelerate that process by removing the tag immediately.
AFAIK new tags pop up in the mods' cue anyway, so it will be killed quickly. But at least now they'll know it wasn't your doing :)