Quite detailed for a beginner, good job there. However there’s something about proportions that bug me. The window makes the desk+chair seem small, and the table is really too small for such a large monitor (its plain bad erconomics + looks a bit weird)
Also i think you have “orthographic” set on the camera, which makes the scene look weird. It’s like the picture was taken from very very far away and then zoomed in. (btw, in the first scene everything is tipping over. Make sure to have what’s vertical, vertical)
The orthographic camera is a bit disconcerting. Now that you know about it maybe you could post some renders in perspective mode? My only other advice would be to put a light of some kind outside the window… or maybe it’s night time? Hard to say. It’s great beginner work, keep us posted on how it goes.