Check out the grasshopper primer. I haven't read it in a while but I used to claim it was written by programmers for non-programmers. Great getting-started guide. Rhino probably still has a demo available, too. Dynamobim.org is another option if you want to try visual programming without an investment. Dynamo is mostly visible for it's connections to other software, e.g., Revit, but can stand alone as in sandbox mode.

EDIT:Yes, it's that grasshopper https://www.rhino3d.com/6/new/grasshopper for a demo reel