Unlike mechanical machines, which you can easily oil and maintain yourself, computerized machines cannot be oiled. The only maintenance on computerized machines is keeping the bobbin area clean after you have completed a project. You want to be sure you clean out the thread dust on a regular basis.
I also think you have your stitch setting on a utility or decorative stitch, maybe the blind hem stitch.
I have heard really good things about these machines, hopefully this will be an easy fix and you'll be happy with it!