How can i gain weight? im 19, 5'5 and 101lbs. i want to gain some more wight so im not just skin and bones!

Muscles and Protein: To gain healthy weight you should eat a diet with sufficient protein to be able to build muscles (10-20% of your diet should be sufficient). You then need to embark on strength training of all your major muscle groups to force your body to increase the size of your muscles. Strength training should be done 3-4 times per week with rest days in between.