Insurance/Decal needed for Permit License Holder ?

Hi All,

I’m in NJ, USA in H1B. I just got the permit license. Now I am eligible to drive with supervised driving. I am wondering if it’s required to have an insurance when I drive my friends car? In worst case, if I get pull over, then can I show the friends insurance and not be in trouble? I know its good to have insurance in my name as well, but I want to confirm if it’s the restriction under law. Also, do I need to put the decals on the car. Since, I am above 21, I believe it’s not necessary right ??

Would really appreciate any feedbacks.