Myheating and air condition fan is not turning in my unit outside. Do you know why?

If the compressor isn't running either, likely the relay is stuck. You can't see the compressor, but should be able to hear it putting away. The breaker could be off, the fuses in the electrical box next to it blown, or it may not be getting the signal from the thermostat. You have 2 small wires from the thermostat that operate a relay switching power from the large wires from the house to the compressor and fan. Power to either set of wires can fail, or the relay not work.