Agreed, Sourceforge is the place to start. Just searching on Minecraft yields a ton of projects. I haven't worked on something at Sourceforge in quite a few years, and wow their search mechanism is really impressive.
I've always learned programming from doing; so, no suggestion on courses for that per se. But as an alternative, I would suggest supporting classes like discrete math, predicate logic, and more abstract computing courses like
https://oli.cmu.edu/courses/free-open/computing-course-details/ . Other non-programming courses to look for would be like operating systems theory or object oriented design (if you can find it decoupled from a language.)
