I put similar advice on another post, so here goes. :)
The healthiest way to make your body how you want it is to:
1) get plenty of rest
2) take good care of your skin, teeth, hair, and pick out flattering clothes that work well for your body size, shape, and color
3) eat a balanced diet and stay hydrated
4) begin a workout routine you feel you can do regularly (few times a week or more). Pick something that sounds both fun and healthy and give it a try.