Is there CarPlay Simulator in Xcode

This can be anwered with both yes and no.

Yes, as in: there are emulators and tools available for Carplay, but only for companies that have enrolled in Apple's MFi Program.

No, as in: it is very likely not available for you or your company, unless you or your clients have multiple manufacturer plants.

If you want further details, I've added a longer answer in the SO question Is iOS CarPlay API Public? How to Integrate CarPlay?.

That being said, there is mentioning of some users who have successfully enabled the Carplay simulator with XCode, like in this question.

Actually there is a CarPlay "External Display" that can be enabled, for it to show up you simply need to type in this command in a Terminal window:

defaults write com.apple.iphonesimulator CarPlay -bool YES

Then shutdown and restart the Simulator.

As of iOS 12 and Xcode 10, CarPlay is available as an "external" display in the Xcode simulator menu.

(Note that this doesn't mean CarPlay will register itself as an additional UIScreen though.)