Drink 2 16 oz cups of whole Milk a day, chocolate milk works too use butter instead of cooking spray, eat hella nuts, sub chicken and fish for beef. Make sure ur getting good amounts of avocado, sweet pitato, when cooking rice use beef broth instead of water. Simple additions and fixes will help you put on weight, went from 160 five foot eleven to 185 gaining no fat in about 8 months. It’s about consistency and swapping low calorie shit for high calorie shit when it comes to us skinny folk. Make sure to not over do your calories tho, rlly only need like 300-500 moar calories a day. It will take time and consistency in the kitchen and the glorious house of gainz but you can do it.