Yeah I would suggest a national park over a beach. Especially this time of year. You will struggle to find a beach or bit of coastline anywhere in NSW during summer that doesn't have at least a few other people on it.

Much easier to find a secluded off-the-track spot in a national park.

I've done it before with a couple of exes. Usually down a secluded fire trail or access road that you are confident not many people will travel down. Fond memory of pumping my first girlfriend full of cum up against a big sandstone boulder somewhere just outside of Lithgow

Don't know if I would organise it with a WL though. Would probably be quite expensive.