Study, though you should take a break every 10 or 20 minutes so that you don't become bored or fall asleep with your studying. Do your best work in school, put your best effort, because if you don't, you won't be as happy as you would have if you did. Ask for help if you don't understand something. Don't be afraid to ask for help and speak up in class, it will break or make your final grade. Communication and listening in class counts a lot on your grades. At 14 years old, you should at least get 9-10 hours of sleep. You should sleep well, too. Like if you slept for 10 hours, but half the night you were worrying about something in your head so you never felt asleep until after like 4 hours after you went to bed. You should fall asleep the minute that you get in bed. Eat healthy foods, like fruits and vegetables. In a day, you should grains - bread, etc, fruits - apples, bananas, etc, vegetables - spinach, lettuce, etc, and meat. You could also eat a little bit of oil and sweets, just not too much, like the amount you're suppose to be eating for grains or fruits. It should be less than that. Also, exercise daily. Since you're in high school, there should be many sports to join and you could also exercise on your own. Either join a sport(s) or exercise on your own - run or do exercises and stretches. Study, do your best in school, eat healthy foods, and exercise.