I also use SketchBookPro on my iMac. Nice, too.
Did you learn how to cook? Did you learn how to play a musical instrument? Did you learn how to drive a car? If you did, I suspect you can learn how to paint. This article by Richard McKinley, http://mckinleystudio.com/, reinforces this idea in his article, "Artistic Drivers Education". http://www.artistsnetwork.com/articles/inspiration-creativity/artistic-drivers-education
There are many useful articles on his Pastel Painters Blog, http://www.artistsnetwork.com/category/art-blogs/pastel-pointers-blog. Most of the articles would apply to other media as well. He is a very learned instructor.