QUESTION ABOUT BODY FAT/MUSCLE, M GAIN?

Ok so im a 16 year old guy that had been working out for about 6 months now and i just got m-peak for m and some whey protein for my after workout, should i make a shake of whey protein, drink half of it before workout and then the rest after? or should i drink everything after? also will it harm me in any way? ;P just curious because ive used a different product before, whey is new to me but i heard that many people use it, also should i get casein protein too if im already using whey? because ive heard that whey protein only last for about 45 mins and casein lasts for like 6-8 hours so that i wont lose any muscles? any advice on that?