When it is your first time entering Sydney, a great start to get a feel for this fantastic city and its size and multitude of different perspectives is by driving all the way to the most northern tip of the southern side of the greater Sydney Harbour, to Watsons Bay.
Take advantage of your campervan as I dare to say that visitors without a car barely ever reach such a remote corner of the city. It is a perfect morning activity before you can check-into your accommodation.
Should you have stayed at the Sydney Tourist Park the day before, as recommended in my Melbourne to Sydney itinerary, it will take you about 50 minutes to drive to Watsons Bay.
Park your van at the Camp Cove Carpark and explore the Hornby and Sydney Heads tip of the peninsula on foot. Grab a freshly squeezed orange juice at the cute Camp Cove Kiosk and observe the local (not touristy at all) beach life. Maybe you will see some triathletes preparing for a swim or a local diver fishing for octopus with his bare hands.
You will take about 15 minutes walking from Camp Cove Beach to reach the Hornby Lighthouse, passing by the Lady Bay Beach and amazing lookouts over the Sydney Harbour and Skyline in the background.
From the Hornby lighthouse, you will get to see the open ocean and the mouth of the famous Sydney Harbour. Across from you, you will see the Manly peninsula, the northern tip of the harbor entrance.
Head back to your van an take the scenic drive along the inner harbor towards the city center and your accommodation.