Why would you not be able to?

Check the regs. I know some states say you can’t be on the phone, even hands free with a provisional so I’m guessing no

Your parents told you it was illegal didn’t they?

CarPlay is integrated into the vehicle’s stereo. There’s no reason you can’t use it. You don’t need to touch your phone at all to use it.

Pay attention to the road and don’t worry about the radio, enough assholes on the road, don’t need anymore

tl;dr it's fine for music or directions in my opinion (not a lawyer) but not for answering phone calls or texting.

Technically, the NJ MVC rules state that for drivers with a GDL or probational license (so, a step up from learners permit) aren't allowed to use a cellphone, not even hands-free. If CarPlay counts as hands-free phone usage, you're not allowed to use it. However, CarPlay for GPS or music is probably fine since that's not prohibited, and this is just how your car gets access to directions/music. You probably shouldn't be answering any phone calls, not even hands-free though.

>Use of a cell phone (hand-held or hands-free), hand-held video games or any other hand-held wireless electronic devices (i.e., ipods, GPS) is prohibited.

Source: https://www.state.nj.us/mvcbiz/pdf/About/GDLBrochure.pdf

This is exactly what happened