I am very thin . My bones r easily visible. I want to gain some muscles on my body. Please help me

I put 20kg,s of lean muscle weight on in 3 years. I used no steroids I'm against them. It was all very srict eating and focusing on training. Heavy legs training produces a natural stimulant for your body to grow and thicken. Find a group of friends no doubt there will be devoted people at the gym. Train with them talk to them. They got plenty of trial and errors which you can learn from.talk to a health food shop clerk its surprising how much they know. Got to point people were asking if I was using banned substances because of size put on in short amount of time. Its not hard. Just need to be devoted. Think positively.