As LG said, it may differ from one state to another, but usually, unless the trade school, is registered, with the labor department, and you have a contractor sponsor you, they don't count the school time, my neighbors son had 200 hours credited, by the good heart, of the contractor, credit for his work hours time, not much time for all his hours, just check into this, so you don't have to start all over, when you do get settled with a contractor.
The job usually comes first, then they register you, with the state, and usually pay for the classes.