Why is my car revving high when I start it?

Hello, does this happen only at idle, and only at a cold start up in the morning? Or does this happen at every start up, and does it surge when driving or does it smooth out once you get going?
I dont believe this car has an Idle Air control valve, it is done electronically now. Have you had the car scanned for any diagnostic trouble codes?

This can be caused by a vacuum leak, a sensor that is out of skewed or out of range, low fuel pressure, dirty throttle body.
If this happens at other times, such as coming to a stop light, or when there is a load on the electrical system, ie head lights on, a/c on, etc, There is a Technical Service Bulletin on a software update for the engine computer.
After a throttle body cleaning, the throttle plates may need a recalibration to be done with a scantool.

Also just one more thing to keep in mind, is that we are coming into spring and a switch over to summer fuel will be happening at gas stations. This can cause some variations in operation until the change over has happened and the weather is warmer.

https://www.2carpros.com/articles/engine-idles-too-high