The motor runs but the drum won’t turn. I was told it just might be a belt. If so, can I change it myself?
Yes you can, just takes a few tools and some time and patience.
Flip up the lint screen door and take out the two screws that hold the top to the cabinet. Flip up the top
Take off the front by taking off the two screws that hold it on, and take off the back panel.
You can put the belt around the drum from the front, and loop it around the idler pulley from the back. If you need to see how it goes, look at the sticky at the top of the Dryer Forum section.
Take advantage of this time to thorough clean out the driver, particularly the blower area.