Gosh, Lydia, I really wouldn't worry too much right now about where you want to go with your life. How old are you; 13? 14? There are very, very few people who end up doing the career they anticipated at the age of 13. I'm nearly 30 and am about to undertake an enormous career change, totally different from what I've been doing for the last 14 years! My mum retrained as a teacher at the age of 45 after working in retail for 25 years!
Why not just enjoy your studies, take subjects you're interested in and then see where they take you? Over the next couple of years you may well find that you develop a better idea of the sorts of things that appeal to you career-wise. Try not to worry too much about what you're going to do when you leave school and beyond; there'll be plenty of time for that!
Good luck x