If you get "nothing" from the heater, (ie no fan):
1) Check fuse in power center.
2) Check thermostat (Remove thermostat and connect the heater wire to ground) to see if the heater will start - replace thermostat if it works).
3) Check current limiter located behind grill of furnace. (see photo)
Any further troubleshooting of NO FAN will result in taking the furnace apart and/or electrical troubleshooting with a volt meter.
If this is beyond your capability, you will need to get a technician to help.