First of all NJ State Law forbids the transfer of a long gun to anyone under the age of 18 or anyone not in possession of a firearms ID card. Were these guns purchased by your parents for you? If so, legally they are still your parent's guns. They are responsible for anything legal with these guns. If your parents didn't buy them for you you're already in trobule.
I couldn't find the cite but if you're under 18 you're supposed to be under the direct supervision of a parent or other responsible party to handle a firearm. Go hunting or targetshooting with your parents or brother or sister over 18? Fine. By yourself no.
Even if you were over 18 you couldn"t just drive around with a gun in your truck. Going to a range, hunting, a gunshop, or on your way home from one of those activities fine. Otherwise, no.
Carry permits are issued for handguns and even if you could get one (have to show a true need) you have to be 21.
Leave the guns at home in NJ unless you're partaking in an "approved" activity. Being 16, a firearms violation will probably follow you to adulthood and you don't want that.
I am really asking so I don't make all firearm owners look irresponsible.
If these guns were purchased by your parents getting caught with them when you're not under their direct supervision will get your parents in trobule.
ps Go to NJSP.org, click on firearms and you can read all the NJ firearms laws.