Great start, but I agree with Marcus (aka d12dozr) in the points mentioned...
In particulat the very strong bump on the floor...
You'll soon learn that it actually doesn't take much to make really great looking and photo realistic renders...
Details in your model and correct material set-up is - in my personal experience - the most important part... π
The background (outside the window) looks weird and another high resolution hdri- or IBL image can change A LOT in the final render...
I've taken the liberty to make a quick tone-mapping and white balance adjustment using Adobe Lightroom - hope you don't mind...
test-su-2.jpg