For this coastal ride you would need to keep an eye on the calendar. The traffic in July and August is bad, and traffic on weekends in July and August is even worse. June, September, and October are good times to take this trip.
In NJ you can hug the coast from Atlantic City all the way to the Cape May. After taking the Cape May ferry to Lewes Delaware, you can head south on Rt 1 along the coast through Delaware. Eventually you will end up passing through the Chesapeake Bay Bridge Tunnel to Virginia Beach. Continue South to the NC Outer Banks for a great coastal ride with some ferry rides along the way. Then South to Wilmington NC and then Myrtle Beach. Enjoy the trip!