You will have a misfire dtc and/or rough idle most of the time

Do you have less then 3 years / 36,000 miles, if yes then take it to the dealer.

There is no reset button under the hood. it sounds like the new radio was installed and the hvac connectors were not connected during the install of the radio.

The tools you will need is a 10mm socket, 14 mm spark plug socket and 4-6 inch extension for the 3/8 ratchet. when looking at the engine bay you will see a orange dip stick just below that you will see for four flat surfaces with wires going to them. un-click the plugs from the coil packs and remove the four 10 mm bolts. Remove the four coil packs with in the tubes you should see the spark plugs if you do then get the spark plug socket and extension and and remove the plugs counter-clockwise. I rec's factory spark plugs so you dont have to gap the plugs. then add a small amount of anti-seas to the plugs and reinstall the them to factory torque. then the coils and connectors.

Possible, you should get a cheap OBD 2 scan tool to check for mis-fire DTCs in the system. But the easy way to check for misfire codes is to look at the mil light when the car is running. misfire will make the mil light flash.