simply rhino has a Rhino.Inside.Revit Essentials Course here. Its paid of course.
If you are looking for free content, Aussie BIM Guru has a whole playlist about it. Some of the node names and icons have changed but much of it is still same. I think its a great source for a beginner.
Also Marcello Sgambelluri has a book for beginners. “The Dynamo and Grasshopper for Revit Cheat Sheet/Reference Manual”. It includes hundreds of working Dynamo scripts and their working counterpart in Grasshopper (for Revit).
There are youtube videos as well. Though they are not courses, I believe there are small tips and tricks people can learn from this videos. RevitKid, Microsol Resources, BIMxt, Yourdesk University videos are just some of them.