Nice for a first iso piece.
I don't know if the furniture standing a bit away from the walls is intentional but to me that looks strange, especially on the bookshelf. On the table though, I think one of the legs(to the extreme right) is too short. You can see that for yourself if you draw a line from the front leg, parallel to the floor line on the right, towards that leg that I think is too short. Extend it until it hits that helping line and it should be alright. You can also fix the wrongly positioned gripe on the right door of the bookshelf by doing that line trick. (Using helping lines like that is generally a nice trick to find the correct positions of things in iso drawings.)
To make the overall appearence of the room more interesting, my only suggestion is to add some texture to the bed and maybe to the walls. And then, what has already been said, add shadows and more detail. Keep going.