Only warm air, must cycle many times

You problem sounds like you have a faulty heating element or maybe the thermostats are faulty.
If you plan to do the repairs yourself, then you will need to remove the back of the dryer and locate the air tube from the blower to the drum, this is where the heating coil and the thermostats are normally located.
You can test the coil and thermostats with a continuity meter and check function.
Good luck
I hope this helps