Any sport or activity requires practice to develop skills and master the same. Exercises such as warming up and stretching your body will keep you fit besides building your stamina. Your physical trainer at school can suggest more exercises related to your game. I can suggest a few things here. Use both feet, as you can’t always use your stronger foot in the game. On a wall, mark an area of 1ft × 1ft. Now practice kicking the ball inside the marked area from a distance of 5 metres. Dribbling, shooting, heading, tackling and defending are other skills of the game which you can learn with practice.