Welcome Stefuny!
Can you take a picture of your presser foot? Usually there's a round thumb screw on the side of the foot that you loosen to take the foot off but some brands like Bernina are different. New feet are available at Sew-Classic.com along with a guide that tells you how to determine which style of foot you need. Sew-Classic also sells replacement controllers so you can get your Kenmore running again too. It never hurts to have a back up machine (or 20).
Rodney