Most wave spots are close enough to a town that the Rangers will give you a ticket if you camp there. The exceptions are Gnaraloo which will be a bit full on for you by the sound of it, and Coronation Beach nr Geraldton which will be perfect for you.
If you don't want to pay for a caravan park and want B&J with easy waves Coronation is IT

I think $5 a night, but you have no amenities at all so you need to take water, food, everything. But 20kn plus, cross shore, 4 days a week, 500m flat water and then small waves out the back getting bigger the further you go out. Perfect intro to waves. It is about 25km north of Geraldton which is a major town.
If you don't mind paying $20 a night for a caravan park us WA guys will be able to suggest many more places eg Lancelin and some Perth spots for good into to waves. Coronation is the pick for conditions AND price though.