Hi, you can improvise the materials first, and then tweak the settings for the GI. Try and use V-ray Sun as this gives you a control over the softness of the shadows. The lighting looks alright but it seems to be too bright. Try and use Reinhard Type under color mapping, with Burn value of .6 or less. This will help in reducing the hotspots and light burns.
For your wood material, use maps for reflection, bump and glossiness, this will give you more realistic results. For all the shaders that you use, try and put a little bit of glossiness, as no surface in reality is matte.
Do not put an ambient light as in your scene I can see that you have used some kind of light behind the camera. This is playing bad for the shadows.
Let me know if you need any other help. I will post the settings which would help you to render in good quality. Also ask your questions in specific so that I can answer them precisely.
Have a nice day.