我应该为这个项目使用什么布局（Java）

I am making a platformer game for a project for class and need to have a chicken character jump on some platforms. I have a start screen and a button, and when the button is clicked, it will change the frame to the first level. When I add the chicken character to the frame as well as the background image, all I can see is the background image. Should I be using a different layout or is there something else I can do. This is my code:I am making a platformer game for a project for