To succeed you must be physically prepared for the hard work that being extraordinary demands. You need energy and enthusiasm. Develop healthy habits by demonstrating the willpower to control your impulses. It is easy to stay sedentary. Get moving. It is easy to gobble fast food. Plan ahead and cook a well balanced meal. Being fit and healthy is really very simple. Begin eating healthy foods and exercising and keep doing it for the rest of your life.
Choose a life sport, a physical activity that interests you that you can enjoy for a lifetime. Given your age, have a goal of becoming an expert at your chosen sport. For most sports, consider ten thousand hours of practice as a guideline for excellence.
Keep moving. Eat mindfully.