Welcome to the board from Southern California!!!!
The walking foot is great for "in the ditch" quilting as well as diagonal quilting or just quilting lines on the quilt. I like to do diagonal quilting a lot on quilts that have the 9 1/2 blocks or even sized blocks. I use a wandering stitch that looks likes hills and valleys. I also like to use a decorative stitch when stitching "in the ditch" or along the piecing lines. It is very hard to stay exactly in the lines so a decorative stitch lets you be "close" without looking like you messed up.
the Walking foot does not work with stitches on your machine that take it backwards, use a regular foot for that. A lot of like to Free Motion Quilt (FMQ) you would use your "embroidery" foot for that one.