Here are the Grasshopper definitions I showed last week, with several variations on how to draw a star.
http://cad2017.christopherspecce.com/wp-content/uploads/2017/10/StarBuilder.zip
As I mentioned in class, the Grasshopper Primer is a great text to start with.
http://grasshopperprimer.com
Another great series is “Grasshopper Getting Started”, which are hosted by David Rutton, who is the creator of Grasshopper. It is from a few years back, but still a good thorough introduction.
https://vimeopro.com/rhino/grasshopper-getting-started-by-david-rutten
Lynda.com also has a 4 hour grasshopper course that looks pretty thorough. All RISD students have free acess to Lynda.com, you just need to register for an account while you are on the campus network. After that, you can access it anywhere. See more here about accessing your Lynda account.
https://www.lynda.com/Grasshopper-tutorials/Up-Running-Grasshopper/174491-2.html
See more options here:
http://www.grasshopper3d.com/page/tutorials-1