You should start simple, create a straight line solid object for ground, and create a object with a simple shape of collision box.
Add only one behavior and adjust it little by little and as soon as you start to understand the behavior itself you add others and see what they do.
Take your time to play with construct and read about the functions and behaviors so you can get really comfortable with the programming.
After that you can easily develop the algorithm to develop the game just the way you want.
I can't help you any further because I'm no expert, but if you really need a sample to follow try looking at the tutorials or at the arcade.