I’m really new to opengl. Could someone post a very simple but complete example that uses glortho to change the coordinate scale so that it matches the screen coordinates? Then do something trivial like draw a triangle?

Using glOrtho is explained on the FAQ on this website, have a look there, you will find tons of OpenGL tutorials on google including what you are looking for.

If you are using Windows and aren’t that familiar with the Win32 API I would suggest that you get GLUT for example to hide the ugly platform dependent stuff.