Sydney has one of the most incredible fireworks show. How can I enjoy it? Ina piece of cake: https://www.sydneynewyearseve.com/vantage-points/.
One of the best place to see the show probably is at Mrs Macquaries Point. Unfortunately this place will get *extremely* crowded and the chance to get a good spot are quite limited, especially if you go after 9-10am.
A good compromise is the Foundation & Friends New Year's Eve Picnic with Friends. It's a *non-free* event but still very affordable compared to the other ones, allows you to BYO food and drinks, it has limited capacity and a very good observation point. Tickets go sold out very quickly!