So I bought a dryer from a friend and the dryer is plugged in, the light is on in the dryer and you can hear the timer but it wont start. I’m completely confused and have a lot of laundry to do. 
can you post the model number off the dryer itself, open the door there is a tag with the model & serial number. Also Try this throw the breaker all the way off wait 10 seconds and turn it back on.
Nat