This is what I was taught:
Walking foot = straight line or gentle curve sewing
Darning or jumping foot = free motion quilting
Harriet Hargrave wrote a very good book on heirloom quilting that covers the basics, including FMQ. When I took her class, if a mchine didn't have a "drop feed dog" switch or cover plate, she recommended punching a small hole in the middle of a business card, positioning the card with hole under the needle and taping it down with painter's tape. The card covers the feed dogs and the single hole helps prevent the fabric from getting squished down into the hole as the foot jumps.
Best of luck! It takes some practice but FMQ can be fun.