The machine does not feed material

The stitch length may have been set to zero - Reselect the proper stitch pattern and length.

The presser foot pressure is set too low - Set presser foot pressure adjustment lever to "normal" or increase foot pressure.

The machine maybe set in button hole mode - set the machine to straight stitch

Feed dogs are in lowered position - Raise feed dogs.

Lint could have gathered under needle plate - Clean out lint from between feed dog teeth