A render farm wont help. Rendering in higher-resolution won't help either.
While there is technically nothing super wrong with your render, it is simply a result of inexperience.
There is no 'trick' to getting nice renders other than lots of time, experience, practice, good design, good modelling, good lighting, good texturing. Unfortunately, most of this is missing from your scene. But we all have to start somewhere, right?
My advice; watch tutorials. I can highly recommend Johannes (VizGuru) - even though he works in FStorm all the lessons are more or less relevant. But as a beginnger you should probably find Corona specific tutorials. YouTube is your friend.
Second piece of advice; find a nice, simple photograph with nice lighting and try to replicate it in 3D.
Good luck mate.