If the symptom is the engine is idling too fast, that is a symptom of a vacuum leak. The places to look are at the vacuum hoses and intake manifold gaskets. The car is too new to have rotted hoses but one could be disconnected. If nothing shows up during a visual inspection, use a spray bottle to squirt water around the intake manifold while the engine is still cold. You will see the water get sucked in by a leak and the engine will slow down momentarily.
The idle air control valve could be sticking too. If it is, the engine speed will not adjust down after starting. If the speed varies at all when you are not pushing the gas pedal, that valve is working.