Kenmores are not intuitive machines. You really need to have a manual and follow the instructions to the letter to get them to work. One step at a time. There is a little chart with each stitch in the book that tells you how to set the machine to get the stitch you want. What foot to use, what throat plate, what cam, what setting on each knob and / or levers. They need to be exact.
"IF" the machine is not seized up and is functioning properly following the directions will give you the stitches you expect. If you don't follow the instructions, weird things can happen.
Joe