a walking foot and a stitch in the ditch foot are the same thing-
a darning foot/free motion foot is the other quilting foot-
use the walking (sid) foot for straight lines-
use a darning(freemotion) foot for curves- free motion quilting-
normally quilting is started in the center- work out toward a side- out toward the other side- out toward the top- out toward the bottom- evenly moving out to keep everything even and wrinkle free.