While idling I noticed the temp gauge showing a high reading.
I immediately turned off the A.C and rolled down my windows. (It is now called a 455 air conditioner. Four windows down at 55 m.p.h. 
My coolant level is fine.
I thinking maybe a cooling fan is malfunctioning or a sensor.
What do you think ?
Thanks.
Remove the radiator cap when the engine is cold.
Start the engine and as the engine idles watch the coolant in the radiator.
If bubbles start forming in the coolant it indicates a blown head gasket.
Tester
While you’re checking that check that the fan(s) are running
Does the temp go back down once above around 30+ mph??
Need to look at live data ECT reading and check the engine temp using an infrared temp gun against the ECT (coolant temp senser) reading in the thermostat area…
From your description, hard to know but if the temp gauge spiked while sitting and not just gradually increased temp, that would be a bad sign. In addition to all the usual suspects like low fluid, thermostat, water pump, etc., one thing often overlooked is bugs covering the radiator to prevent air flow. Especially after summer driving.