Hi, Have you done your GCSES yet? Look for apprenticeships before you take your exams, do them and then when you get your grades start your apprenticeship.
Isn't it the law now that you have to stay in education/apprenticeship until 18? I can't imagine they would let you leave unless you've secured one and that it's been confirmed
It would depend on your age. I started my A levels and decided I was unhappy so I left and spent a few months no longer in school but looking for an apprenticeship. If you haven't yet taken your GCSEs though, you will have to take them and start your apprenticeship afterwards.