Radio Island isn't exactly ocean beach but can be pretty good fishing at times, is handicap accessible and has nice calm water as opposed to rough surf. This time of year you will pick up mullet, bait stealers, an occasional drum and flounder. Fort Macon is another option. It can be a relatively long walk , but most of it is on hard packed sand. Drop your folks and gear off at the gate that takes you to the rock jetty and park your vehicle and go meet them. If you are looking to drive on the beach other than the OBX I can't really help you. Maybe Topsail or a Wilmington Beach allows that this time of year. I do know that I camped on a beach in Wilmington 7-8 years ago that allowed us to drive on the beach at that was July 4th.