Definitely not too bad on the materials, particularly the tile and granite. Lighting needs work though. I haven’t seen a sink that square in a long time either, so that may be a good thing to improve upon later. In addition, is that in the back supposed to be a painting, or a window?
In particular, I think you should experiment with lighting as it’s quite a crucial component in attaining a superior result, and can help you in finding what needs work and improving on it.
1: The big water blob of death? I have no idea what that is. Maybe a few more samples can help or move that somewhere where it can be seen better.
2: You seem to be having some weird reflections here. Probably because of the geometry.
3: No interest. It’s all dark. Add an exterior image or something that can keep the eye interested.
Hope that didn’t sound too harsh, it’s meant to help and good luck!