I was skinny my whole life. I did crazy research and dedication to change my body. The diet that I used helped me a lot.
I was around 6 feet 1 or 6 feet 2 in high school and lanky as fuck. If you want to gain quality muscle, do not just eat shitty muscle weight gainers you can buy in a container. Trust me. Those are filled with sugar and garbage ingredients. Do not use creatine right away. Get in lifting first and make gains and get into the routine. You don't want to just go straight into creatine like an idiot. If you are skinny, first thing is to use a bulking calorie calculator.
http://www.iifym.com/iifym-calculator/
Use that to find out your calorie and macros needs.
Second, go to the gym and do heavy compound lifts. Tears more muscle fibers, uses more muscles for lifts, increases testosterone, and increases muscle mass. Leave the pussy isolation workouts for later or do them for some body parts that are lacking. Include CARDIO AND WARM UPS before you hit the heavy weights. I speak from experiences and a lot of injuries. DO NOT SKIP THEM! WARM UP IS NECCESSARY! I have a fucked up shoulder, wrists, elbows, and right knee from going in without warming up. Plus, FORM is important.
Third, get enough sleep. Take daily vitamins, fish oil pills, and joint pills. Drink plenty of water. Limit juice before or after workout. Buy shoes that are meant to be used for being active. Weight lifting gloves are good to grip the weights better. Chalk if you want to do heavy deadlifting. Do not overdo your muscles. It takes time to micro tear the muscles and protein will fill in the tears and make the muscle stronger and bigger so you can go hard your next lift session.
