How to muscle up my body in 1 month or less.?

im 14 and i really need to enhance my body feature this summer. I have been working out and saw some good but a little enhancement especially in my chest part. any ideas or tips? should i really focus on doing hard and some cardio activities this summer? please i need suggestion.(if your going to ask me about buying fat burning medicines dont just answer me cause im still a kid) thank you.