set up the scene

I would like to set up the scene first. I need two walls and ground as the background. The position of the model should be hangs from the celling so that I can get the shadow on the ground. The two lights are separate from the front side and left side which can let the shadow project on the walls.
I illustrate pink,blue and yellow colours as the lights colours which also means three different shapes and shadows. Combined the things together in one object is the style how my model surprised the people.