I'm 20yr old boy.weight 63kg and height 5'5".i'm going gym sice july.i ate 2.5lbs of universal fast gain 3100 supplement.but no difference.help me?

Healthy food...: Learning healthy habits - nutrient rich whole foods, lean proteins, small amounts of healthy fats (avocado, coconut oil), small regular meals (5-6 per day), regular exercise (cardiovascular and strength training) - is best for you. I would recommend against artificial/chemical supplements to gain weight. Your BMI is in the healthy range now, if you are looking to gain muscle that takes time