Royal National Park - North Era Camp group

Myself and my husband were hoping to walk the 2 day coastal walk in the Royal National Park this weekend. I phoned to book North Era Camp ground but they are all booked up till December time.
Are there no other campsites at all on this route? Weekend weather is meant to be good and would love to get away. Any suggestions would be helpful. Did the six foot track two weekends ago.
Based in Sydney. t/y
Are there no other campsites at all on this route? Weekend weather is meant to be good and would love to get away. Any suggestions would be helpful. Did the six foot track two weekends ago.
Based in Sydney. t/y