Hi Janet,
When testing / checking any fuses,wiring or switches UNPLUG from mains socket first.
Test in this order and see if the saw runs after each test.
First unplug the saw and check the mains outlet by plugging in something you know works.
Test or replace the fuse in the mains plug, if it is not blown you will have a spare.
Test or replace the fuse in the saw, if it is not blown you will have a spare.
Check all wiring for loose or broken wires starting at the main plug and finishing at the motor
Check and clean the switch.
If the saw will still not run its time to consult a professional
Good luck
Mick