Sun Skylight Environment HDR Box Light

I’m pretty new to Rhino and I’m having significant difficulty coordinating the sun, skylight, environment, and related rendering tools. All of this is in the “Rendering” mode just under shadows (not a full render).

Sun: when on, my sun actually sometimes behaves in the reverse of how one would expect a sun to perform, meaning sunlit surfaces go darker and shadow surfaces get brighter. How did I achieve that?

Sun and skylight. One or the other is often to dim and together make everything super high key and wipe out detail. The skylight took by itself often blows out highlights. (None of my materials are set to more than 1.0 for gain or amplitude).

Box light. I watched a utube video and tried that and it crashed.

Shadows. When the sun is on, my shadows turn black, unless I give the object at least 1% bump. When the bump is on, even 5%, it very much softens corners.

There are so many choices to combine, I need to move from trial and error to a plan. I did not find the Rhino manual or utube videos to be very helpful. Question (alas): Does somebody publish a textbook or something similar recommending how to combine all these tools efficiently for one’s end purpose, whether it is rendering in real time or a final rendering? Is there an easy peasy plug in?

Thanks, Jeff