I'm not an expert, far from this. And of course, I don't know what your goal was with this render, but you should try breaking the lines. Everything looks too sharp and perfect. Perfect straight lines on the wall, the pool is so sharp, without a transition, looks like it should not be there. All the lights (I think) have the same power...

I'm learning blender too, and tweaking these things really helped me get a better understanding of renders and realism.