Doing well at school helps you get a job later or helps you get into that course you may want to do. The more you want the more you have to do well to get to where you are going, the harder you will study. You need to set yourself some short-term goals, and some long term goals to achieve your success in study.
Study is best in a quiet place away from family, noise and television.
It is best to have a permanent spot with desk, chair and a good light, a shelf and a storage place for your notes. Find out by experience when you concentrate best early morning, straight after school, or later in the evening. Early in the year, make a timetable for study times. Try hard to stick to it . Aim low and try to beat it.