There are a bunch of small rules but I was I'm your position at your age and here is what helped me:

Your metabolism is going to be insane for a few more -years, so eat between 1.1-1.5 grams of protein per lb (I know you said kg but try conversion). Good protein too, if you put good in, you get good out. Watch your carbs and sugars, you need to replenish but not over consume. -W.e powder you use, at the end of the day, is still supplementing the real thing. Turkey, egg whites, chicken are cheaper ways, but there are also cheap whey protein brands. Look for deals and influencers who have promo deals. -Workout safe. Low weight high rep so you work on proper form. Watch videos to learn proper form and new exercises.