Hello Mae,
First of all make sure you are using a good thread, make sure that your needle is in the correct way round, make sure you have the machine threaded properly and the tensions set properly, usually about number 4 or 5, make sure you have the bobbin the bobbin case correctly, these are all the most common things for causing thread to break.
ken
drivewithken@blueyonder.co.uk, July 2007