Machine works but doesnt move forward

Could be that the feed dog is in the down position. The feed dog consists of serrated sections which move together under the fabric and move it under the needle. Run the machine unthreaded and you should see the serrated sections lift above the needle plate, move forward and then drop again. If this doesn't happen the "drop feed dog" knob on the front of the machine could be pushed in. Look for a small knob about 1/2 inch across on the right front of the machine. Push on it and move it sideways at the same time. If it pops out this means that the feed dog is now up and you should be able to sew.