Overall not too bad, but I would say its more of a beginners scene. The first thing I would start with is adding colour to your lighting. Judging by the background image and the position of the shadows it looks to me like its an early morning scene, therefore, I suggest making your main lighting source a warm yellow - orange colour, as well as a cool blue colour for the main world.
The next thing is your scene is incredibly high contrast in comparison to your background image. I would suggest a few things here, starting with increasing the contrast of your background image, and then slightly lowering the contrast of your main scene. Next thing to help with this is to add fog, this will do two things, emphasis that the time is early in the morning, and help match the contrast of the scene with the background image.
Third thing is it looks like a normal render, thats been cut in half, and flipped, its to symmetrical. Add some variation, like for example rocks, randomly scale the bushes around, change the colour of the leaves, add some patches in the grass, add variation in the path and so on.
That is about all I have to say about that, hope all this helps and I really hope its not too harsh!