Can students start an apprenticeship while they are still at school?
I think they can and should. Instead of just studying text books and facing exams, students must be refered to learn art, crafts , skills, vocation training or part time jobs as you mentioned according to new labour market trends.
That will help studens to gain new life experiences, skills and to find their passion. Finland is already on a misson of making a new educational policy combined more with real life.