Work extra hard on your school studies so you can qualify your exams to later become a
professional. Please consider becoming a doctor because there are never enough GPs and medical staff to cover the UK population. For this, the subjects you need are: Organic chemistry, general chemistry, biology, English, physics, sociology, psychology, math and calculus. All those will be included in your undergraduate coursework.
Cease all your social networking to buckle down and graft hard to get the highest grades, during which you may lose your friends because you'll be too tired to socialise. Because to become a professional, your path is never going to be easy. Except there are great benefits.