I was in a very similar situation when I was desperate for my first Salmon. After many attempts in many places, I find beaches to be the easiest. You will find Salmon present on almost every beach, so I would imagine Northern Beaches to be good.
I fish with a 12ft rod (10ft should also be ok) and use the simple rig below (or other variations of it), a size 3/0 or even 4/0 gang hooks with a full pilchard. Other times I will use a double hook with a strip of fish (Mackerel, mullet, stripey, etc)
Basically just cast in the gutter, and you should be in luck if there is any Salmon around. My preferred times for beach fishing is a couple of hours before sunset to a couple of hours after, so I usually time the rising tide around this period and fish those days.
I think with a bit of luck, it will be a matter of time before you land a Salmon. 2 out of 3 trips to the beach I usually catch Salmon.