First of all, it is definitely not enough to gain muscle for one month. Even with the guidance of a professional coach, it will take about three months to have good results. You shouldn't have practiced before. Let me give you some advice:

1: If you want to gain muscle quickly in a short time, you don't need to look it up online. Just ask the personal trainer directly. Find a better personal trainer, have 3-4 classes a week, and give all-round guidance. It will have a good effect in about three months. Because even if I tell you how to do it, it is not standard, and I can't grasp it myself.

2. It is suggested to have a little foundation before making a fitness plan. It's almost impossible to do it at first. You want to practice so much. You should always practice chest three-headed, back two triangles, and cycle once a week or so. It was hard to recover at first.

Swimming can exercise heart and lung function, but it has no obvious effect on long muscles. Want to grow muscle is weight+diet.

Diet is only to supplement protein after practice, and eat more whole grains, vegetables, lean meat, chicken breast and so on. No special recipes are needed at first.

Personally, I think fitness is a long-term thing. Even if it works in a short time, it is difficult to maintain. Once I stop exercising, I will go back soon. Only long-term regular fitness can stabilize my muscles. I hope I can help you.