Oh man. You really need to go back and read through the tutorials and manual.
First off, your background does not need a physics behavior. Remove it.
Second, use an event "On Start of Layout > Set BackGround Image to WindowWidth /2, WindowHeight /2.
or better yet,
Third, use a tiled background. Create a small strip of blue about 24 pixels wide and the window height size for the height. NOT the layout size. Set that graphic as a tiled background and set it on its own layer. With a layer parallax of 0, 0. Then add in your clouds as sprites above the layer the background is now on.
Fourth, don't even consider this to be "done soon." I highly recommend starting with the beginner tutorials found here.
Fifth, come back with all of your questions, you will have a lot, and the community/myself will try to answer them as best we can.