Tips for a first timer in GYM?

Posted: 31 Jul 2015 12:19 AM PDT

I'm about to go to the gym for the first time in my life, I am 15 years old, 5'11 and a mesomorph I have a body of a grown man, but nonetheless still fragile Can anyone please give me some pointers for the days i should do my legs, arms , etc... would really appreciate it. Also diet and how much protein should I take in 1 day.