realistically, you should know exactly how to diet and grow new muscle before you start to cycle. steroids work by speeding up whats an already solid game plan. the more solid of a foundation you have, the more you will get out of them. judging my your weight, at your height, you have some room to improve. it's not a great idea to run gear at your age. there is a chance that it can stunt your growth. you may not grow taller, but from what i understand, there are long bones in your body that will continue to grow for another couple years. starting now may limit things like how wide your shoulders become.
at this stage, i would start by consistently getting about 2 grams of protein per lb of weight. about 300g would be good. you can have a couple of shakes to fill areas of your diet in, but they wont help you gain like real food. so make sure that you're getting at least 200g of solid food protein from animal sources. eat every 2 to 2.5 hours and split that protein up through your meals. from there, start adding in carbs. you can start with about 200-300 carbs a day and over time, add more carbs to the diet until you see that you have reached your limit. when you see that you're adding too much fat, you'll know to cut the carbs back a little.
so get this going, and really put some work into it. this is where your foundation will be. this is where the real work of bodybuilding comes in. then when the time is right, come on back and we'll talk steroid cycles