For my whole life I have always been very skinny. My metabolism is so fast it's unbelievable. Well anyways I'm 18 years old. 5'11 and 118 lbs. I want to gain weight but not by getting fat. I would much rather just build a lot of muscle. I understand it takes a lot of time, patience, and hard work. I'm basically looking for tips on getting started. Any good foods to eat. What to watch for in foods. Any help would be much appreciated.
Beef, poultry and fish need to be a massive part of your diet. You also need starchy carbohydrates and fibrous carbohydrates in your meals. Also if you are trying to gain weight quicker then add some healthy caloric dense fats to your diet, like all nut butters, avocados and coconut oil. Take a protein blend with milk, use fish oil and take a multivitamin. You also need to be lifting heavy and your workout should be pretty much all compound movements. You want to get good at squatting, dead lifting and bench pressing.
Aim to get around 4000 calories a day; there is no way you will stay skinny with heavy lifting and massive caloric intake.
start weight training upperbody and lower body both. Also do cardio. But I wouldn't start anything until you first get to 130 pounds slowly by eating more. I was once 129 pounds, at 6'0 2 years ago. I had stopped exercising after competing collegiately in soccer... dunno but I lost motivation at that time and dropped to 129. Anyway the past 2 years I took up marijuana, and started training like a mad man + great nutrition. I weigh 163-165 pounds now very cut, under 10% BF for sure haven't measured. Best shape of my life. What you need to do is EAT. Eat healthy, but eat at a surplus. I started off at 129 pounds making sure I ate 4,000 calories a day. Before that I wasn't keeping track and probably didn't even get in 2,000 calories a day. Pasta is your friend, breads, Peanut Butter was and is still my best friend, nothing wrong with moderation of junk food like Pop Tarts or ice cream. Make sure you get your fats in, proteins in, carbs in, most of all gotta be surplus calories. You will never get fat OP. Just understand that, it takes a long time to put on weight, I barely reached 160 recently after 3 years of hard work. So 15 pounds a year roughly. Once you reach desired weight (doesn't happen over night) then you can stop with the surplus and probably just settle around 3,000 calories a day and maintain your body. But at sub 120 pounds, I wouldn't train at all until you got to 130, that is dangerous you will get hurt.
^ You wont get hurt training like the poster above says, that is unless you use too heavy of weights or shitty form. Like Killerkush said if you lift heavy and you have a caloric surplus then you WILL gain weight. Maybe invest in buying a mass gainer protein. The one I use has in one serving 1000+ calories 60grams protein and like 116 grams of carbs.