Plz helpppppp?

okk i wnt to gain weight by end of Dec.. i am 18 yrs old, 5'2 96 lbs now. i want to gain 15 lbs . i am going to buy ensure weight gain shake and drink it 3 times a day also on top of 3 meals and snacks a day.. would that work? it is very diff for me to gain weight...I want to gain fat weight but in the right places.. now muscle weight.