Hello guys, I’ve been following blender tutorials for about a month and decided to make my on little project from scratch. I’m looking for feedback so please give me your opinion 
Since you’re new to 3d world I guess I should tell you that it’s a good result.
I’ll give you an advice:
Take a photo of your room from the same point of view.
Put the 2 pics side by side and spot the differences.
Improve them and don’t give up until the 2 pics are 80% identical.
Never think it’s impossible to make them match. Never. It’s just that you’re not able yet.
…
Then call the guard and tell him to dismiss jail’s decorator. 
Jokes apart do what I’ve said with photo and you should spot easily the weak points of your work.
Some solid advice from LazyVirus there. Looking at real-world reference is always important (essential, I’d say) to get things looking right.
For a first project you are off to a good start. Some things I notice:
The scene seems tiny, almost as if it’s a miniature house. The stucco / concrete texture on the wall contributes to that, as it seems way too big to me.
A nice way to help with getting the scale right is to make sure you are modeling in real-world units. Using actual measurements ensures the scale looks right. Here’s a screenshot from Blender 2.78 showing where to find the Units menu:
If unsure, I sometimes make a placeholder object that’s the height of an average person (something like 1.7m) to check if the objects look about the right size compared to each other.
As the 2 above said, look at reference. And another tip, don’t have light coming from the outside and a lamp on the inside that is turned on. Limit yourself to one light source. That will probably improve it a lot. I mean, you don’t turn on the lights in your room during the day either, right?