You don't need to cut - you don't have the fat TO cut, and if you get leaner, will just look skinny. To gain muscle mass, just calculate your Maintenance and make sure you are eating MORE than that - although, at your age and weight, you should honestly just be able to eat about anything and train hard, and as long as you're eating enough, you should get results if you're training properly and hard.
At your age, forget ANY supplements but the basics (creatine, multivitamin, good fats, protein, BCAAs) - and even then, you don't need these if you get enough in your diet, and at your weight, you should easily be able to get enough good fats, protein, and BCAAs. Wait until you're at LEAST 18 years old, and have an extensive training history and base, before thinking about using any other supplements but the basic staples. In the meantime, you can educate yourself about different supplements and what they do - and should already be doing this re the basics - but you shouldn't be considering using any.
Forget about stupid diets, especially if you want real results. Having 16 servings of milk daily is FAR from ideal for bulking OR cutting - and you should be able to have this on TOP of your regular food. You should be focusing more on PROPER NUTRITION, and actually eating REAL food, 5-6 meals daily. I recommend learning about proper nutrition - lots of sites around for great information, or even just browse - so that you understand why you need it, and how you can achieve it, instead of using fad diets. Nutrition should be a LIFESTYLE.
Re training, I also recommend doing some extensive research on different methods and ways of achieving muscle accretion.
Honestly, your dad should ALREADY have told you all this.
~Team APPNUT