At 16 years old you've got no business using supplements unless you're a semi pro-pro level athlete. Focus on studying and learning how your body works, what you need to fuel your body to reach your goals and what you need to do in the gym to produce results. Whilst your doing this, begin trialling what you learn and figure out what methods work for you - keep a track of how your body responds and eventually you will find the most effective methods for YOU. Everyone is different and responds differently to training methods and food - it's al about learning your body in this game.
The other reason is you will make great progress without supplements initially so try and hold out until atleast 18 I'd say. Don't use all your aces at once, otherwise you have nothing to introduce when things start slowing up. Once things start or stop developing and you feel you've done all you can to improve your knowledge and experience, that's when you introduce a few supplements to give you a little push. Develop a solid base first so you're not dependant on those supplements.