Welcome to the Central Coast, although I no longer live there, there are some places you can go.
For learning to surf, I'd consider the southern end of Terrigal but not the Haven ( that's a big wave spot), try also South Avoca but not the point, and south Shelly beach, they are the closest to beaches good for learning but choose your days carefully.
There are also boardriders' clubs both long and short
Socially if you like sports then Mingara Club at Tumbi Umbi is a sports club with lots of different teams in different sports, each town up there has various sports teams and that may be a way to socialise.
There is also the Gosford Leagues club but IMO it's not so nice ( at least I didn't think so when I lived there)
I know too there are clubs that are associations of people from their country of origin, like a German club a Greek club etc, they may be a help too but the best clubs are where there is a great mix from everywhere
Great surf territory up there, enjoy. Go watch the haven or Foresters on a big day
I've taken up troll hunting just for fun, instead of a rifle I'll just use a pun! 冲浪爷爷