Your dryer needs three things to work.
Your dryer needs 240 volts to heat it will run on 1120 volts but it wont heat. Go to the breaker and turn it off then on again if it works great you might have had a power surge. You should be fine. If it keeps tripping the breaker call for service . If you have 240 volts but no heat it could be the heating element, thermal cut off, terminal block or the thermostat. Call for Appliance repair specialist.
Dryer wont tumble
If you hear the motor running but the drum is not tumbling it is most likely the belt. While your in there you should check the pulley if it is bad change it because the belt will not last long with a bad pulley
Dryer is not working at all
Check the breaker if you have 240 volts then check the door switch. If is is broke change it this will keep the dryer from running. IF THIS IS ALL GOOD CALL APPLIANCE REPAIR SPECIALIST.
Heats but takes to long to dry
If the drum is turning then you should pull the vent off the back of the dryer and make sure the air flow is strong if you have good air flow check the vent ducts in the house if they are clogged clean them out. If it still takes to long cal appliance repair specialist.