Dougr given this is your fist time out on new gear and you are just starting out, I'd definitely go Narabeen, it will be safer.
However being a SW /W breeze it will be very gusty and challenging, you'll get big bullets of wind that will probably wipe you out, so hang loose. Also some parts of narabeen are quite shallow so take it easy near the shore areas.
I'l be out at La Peroeuse as soon as I get work out of the way..