Newcastle City Beach is located near Newcastle East light rail station, it's the most popular beach known for tourists along with Nobbys Beach. I lived in Newcastle for 5 years and all I can say is Newcastle and it's beaches are the best on the east coast of Australia.
The beach in Newcastle is also superb! From the train station, take the light rail and walk 2 minutes to the beach. The sea is completely cool, the sun is shining, the sand is soft and delicate, and there are few people and beautiful scenery. It is highly recommended!