What should my 1st steps be with no experience to fix a truck 2011 model tahoe.

 

You'll need to see if you have coolant running through the lines, The A/C will normally shut down if the engine is too hot, If that is the case
and its checked with a thermometer, then something else is amiss.

 

Look for low coolant or a coolant leak, talking about anti-freeze/coolant, not AC refrigerant here. Need to address engine hot issues.

If low on coolant, add and then run engine and check for leaks; common areas can be the hoses, the plastic radiator end caps, the heater connections (especially at the plastic connectors at the firewall), and the water pump.

Consider having it towed to a shop, they can use a cooling system pressure check device to find leaks.

 

Are you saying you turned off the A/C and the hot engine light came on?
or
the A/C turned off and hot engine light came on around same time?

 

This could also be due to a bad temp sensor, or sensor wiring if no leaks are present.

 

I had this same issue ended up replacing the temperature sensor and it fixed the issue

 

Make sure the electric fans in the engine compartment are BOTH operating.