Begin your coastal drive either at San Clemente (south end), or at Seal Beach on the north (even in the middle at Laguna Beach!). There are hundreds of things to see and do, for everyone's interest. The main 'star' of the coast is the beaches; from wide, long sandy spans, to intimate coves and rocky shores. There is even Bolsa Chica wildlife refuge between Sunset Beach and Huntington Beach. Bicycling trails abound... more than one pier, a ferry trip at Balboa Island, and many snorkeling or scuba-diving places along the route.
I can't begin to cover all the attractions, beaches, restaurants, even art galleries. There are plenty of details -- covering your interests -- online.... including Tripadvisor. Try searching "Orange County, California coast", and even the names of the beach cities: Listed from north to south, check-out Seal Beach - Sunset Beach - Huntington Beach - Newport Beach - Corona Del Mar - Crystal Cove - Laguna Beach - South Laguna - Laguna Niguel - Dana Point - Doheny - San Clemente.
There are many places to launch rent kayaks to cabin cruisers, surfboards (etc), and even whale-watching trips out of Newport Beach or Dana Point Harbor.
John Wayne Airport is just a few minutes drive, centrally located inland from Newport Beach. A Tripadvisor hotel search will show a head-spinning selection of hotels and other lodging, and even more restaurants. And you cannot miss having dinner at one of the many waterfront dining spots, including Newport, Corona Del Mar, Laguna, Dana Point Harbor.
The Orange County coast still amazes me, a native Californian. It can be very expensive, but it's possible with good planning to see it on a much smaller budget. It can be crowded any time of the year, but of course, the warmer it is, the more people will have the same idea as you! Be patient, the traffic can be busy, but bearable; 'traffic' gives your passengers a great people-watching opportunity!
Make your reservations well in advance - bring your cameras and wear a good quality sunscreen! You won't be bored. Happy 'coasting'!