Sorry for the delay in getting to your question.
Can you post the model number of the dryer please.
If you start it going do you hear the motor running?
If you open the door and turn the drum by hand does it spin round very easy?
Ok what you need to do is remove the top panel of the dryer and from there you will see the drum. Have a look on there and see if you can see the belt around the drum. If so lift it up and see if its broken. But make sure you unplug the dryer first before removing the top panel.
If so then the belt will need to be replaced from there.
But if the drum isnt turning by hand then with the top off try and push it as hard as you can as with it not being used the drum could have siezed up so turning it can free it.
Then just replace the belt and see how it goes from there.
Let me know what you find.
Just 2 screws at the back.
Remove then and then slide the top panel backwards and it will come off.