There is a good surfing beach an hour or so from Barrenjoey. We went down today. The drive will take you past Hahndorf through to Mt Barker and then to Strathalbyn.
Middleton Beach is one of the best beaches to learn to surf, anywhere. This is because the fine sand packs down hard and flat to create a safe beginners environment.
A few kilometres either side of Middleton is Port Elliot and Goolwa. Both worth a visit.