Hey Monkeykiter,
Good question,
Cronulla is a great spot but easterlies are rarely more than about 10 knots and are a bit rare anyway. Normally either NE (seabreeze) or Souwest which is either off shore or onshore and windy in the area you mention. SE is a bit onshore and Westerly is a no no if you are learning for obvious reasons.
Kurnell can be good if you keep away from the crowds and go to Bonna Point in a NE just in froont of the toilet block but it can be busy on weekends.
Brighton in front or slightly S of the Novatel is OK in NE or S. Most other places are ocean beaches with large shoreys

Best bet is to travel a bit like make a day of it and go to Newcastle or down to wollongong and hit lake Illawarra (don't mind the pelican itch), lots of empty beaches and sand.
Loads of Peeps go to "the Bay" because it is one of the only decent spots for flat water in Sydney. Best of luck, might have to battle with the crowds at Dolls or B le Sands.
Good winds and Peace