I was down there last week to be honest its not a place to learn its open surf with no flat water. I didn't see any hire trailers for windsurfers only kayaks & surf gear.
The only place I can think of on your way would be Jordan's Boat Hire at Port Macquarie. Ive traveled up & down the north NSW coast & there is not much in the way of windsurfing spots until the Port down.
Maybe some hire gear at Broadwater past Surfers Pardise you could try Surf fx there they might help.