Take advantage of your exposure to people and get to know as many as you possibly can. You never know when somebody you've met could be the key to your future. You have to get in front of the camera, or hit the runway, and gain experience. The name of the game is selling clothes, and some of the most successful models have been those who had a feeling for the garment they were wearing, who took special care to show it off in the best possible way. It's your body, and your life.
Most models have to watch their diet, but avoid using legal and illegal drugs to help.
That includes cigarettes. They will show up on your face sooner than you think. Keep active, eat healthy, and get plenty of sleep. Have fun, but use your common sense. Sense of Humor.