Codewarrior comes with a demo program called SillyBalls. Use
that as a template; it'll set up a graphics window and draw
a bunch of circles. To plot lines you use routines called
MoveTo and LineTo, if I recall correctly. Look these up
in Inside Macintosh or some other reference book on quickdraw.
Or just experiment. Both MoveTo and LineTo take two parameters,
the horizontal and vertical coordinates in pixels. Everything
is in absolute coordinates, measured from the corner of the
window; this is rather different, I believe, from turtle graphics.