Gaining muscle?

Hi! I am 16 years old and am very puny!! I weigh like 112 lbs and am 5’9″….I naturally have a slender build, and that’s good for getting cut…I mean I have a set of six pack abs and I only do like 50 crunches a day….What I want is to get bulkier…I want bigger Pecs, Biceps, calves, and thighs…My goal weight is like 170 lbs by the time next october comes along…So about a year….Considering how underweight I am, I may be able to gain some quickly, but I have already increased my caloric intake from 2000-2100 all the way to 2800-3000 calories a day for the past wo months and have seen absolutely no results!!! I do not lift weights, but I do exercise regularly..Do you think weightlifting could be the missing link here?? And if not, what can I do?? I want to make the football team next year….
Oh and I also want bigger shoulders and a back
Ok people, I asked to gain wweight not if you thought I should gain weight..I am underwight and most guys my age weigh at LEASR 150 and that’s in muscle not like those fat kids…please answer the question that I asked