At 18 bro you can do a lot with just diet and exercise. This is the point in your life when your natural testosterone production is at its PEAK! I know it is hard to stay away from juice if it is readily available, but IMO it is the best decision for you at this point. GL bro, do a lot of reading on exercise, diet, and steroids, so that way if and when you do decide to use, you will really be ready.