1.There is a big switch outside by your unit, is the power on?
2.Have someone check the fuses if there are any inside the switch box outside.
3. More than likely its your starter (Capacitor) They go bad and cause the outside unit not to start.
They dont cost much maybe 12.00 unless you have to get a tech to change it.
Any of your friend that have ac may know anout this part and may be able to show it to you.
Its a oval shaped canister with 2 wires that plug into the top of it. Simple to change. An ac parts store sell them, or try Grainger
Just make sure inside and outside power is off.
You may also have a bad fan motor, does the motor smell burnt ? does it spin freely ?
If you do any work on the unit make sure the power is off inside and outside.
Dont take any chances with electicity if your not familiar, call a tech.