Iphone 11 with 5w charger....want to get the 18w charger.

Dear Community: I just bought an iphone 11, which comes with the 5w charger. I would like to buy the 18w charger and get the Lightning to USB-c Cable. Will this work? I just want to make sure this won't damage my phone.

Also, I found it interesting that the iphone 11 came with Lightning to USB cable, where as the 18w charger requires a lightning to USB-C cable. Any ideas why?

Thank you!

Jim