How do I ad my Apple Carplay to my list of devices?

Just leased a 2019 Kia Sportage. Love the fact it came with Apple Carplay....cannot navigate it.

Very frustrating to say the least. Went back to Kia, but the service guy didn’t know how to work an iphone. Where can I learn how to operate this? Maps show, but no sound. Music mutes but not map sounds. Home button on brings up Siri, but does not take me back to Home Screen. Tried using Maps and also Waze, still too many problems which are making driving quite difficult.