Well, exceptions are rare. Sometimes people with family already in that line of work may get their foot in the door or sometimes extreme intelligence may play a factor in allowing someone to bypass schooling altogether.

But as for your previous question, yes, there are schools to help prepare. Education is highly sought after for people my age back home. Though, to be honest, I may have preferred the way your world did things. The exams must have been difficult to pass without the schooling to train you.

[ And Light would have liked the challenge. ]