My friend, the question you asked is very systematic and professional. If you don't know your usual diet and training habits, you can't answer all your questions clearly in one or two sentences and achieve effective goals. But a few things are certain,

First, you need to gain weight. On the basis of your existing intake of protein, increase the intake of carbohydrates such as rice, bread, and meat, vegetables and fruits. Put oxygen for a while, and the target weight should increase at least 10 kg. Weight gain is very important for you to gain muscle and weight.

Second, you need to increase your muscles. You should arrange at least 4 to 5 days of training seven days a week. At first, it takes 1 to 1 half an hour, with a large band and a small band every day, such as chest muscles and triceps, back and head, legs and shoulders. Each muscle group has four movements, and each movement is about 10- 15 times. The action is very detailed.

Third, you need to be stable. Increasing muscle and weight is a gradual process. Don't be impatient. Don't think that there will be rapid changes in a month or two. That's unrealistic. You should exercise and eat scientifically and in a planned way. I feel that you are still young, as long as you are willing to stick to it! Hold on! Hold on! Take fitness as a part of life, form this habit, and change it day by day! Good luck!