You're finally cool and adulthood is fast approaching, great! But hold everything and take a reality check. Adults have responsibilities and your paperound won't support you financially in ten years time. If you think about it, the future's fairly hazy. GCSE's are the first in a number of qualifications that you can take, to show the world how good you are. The more you get and the better your grades are, the better the chances of you getting a good job and living the good life!
Now's the time to take your education seriously. It's important to keep up to date with your work, not to annoy the teachers and to try and finish your homework on time. Make sure that your writing is legible, because you've got to revise it all in two years time.
COURSEWORK - these days most GCSE's involve coursework of some kind. It's simple a posh name for homework, which counts as part of your exam mark. It is important to find out what % of the final mark is coursework based. This will give you an indication of how hard you'll have to work on it. It is also important to make sure you know when each piece is meant to be handed in. Most schools stagger coursework deadlines to make sure that you don't become overloaded, so don't panic.
REVISION - throughout the last two years of secondary school, exams play a major role. It is most likely that you will have a major set of exams in Year Ten, with both mock GCSE's and the real McCoys themselves in Year Eleven. If you are taking a modular course, your GCSE exams for that subject will be spread throughout the year, so make sure you know which exams count for the final grade.