When is the best time to visit Australia?

I am currently making plans to visit Australia on my honeymoon. I live in Florida, USA now and was wondering when the weather would be just right? Not too hot, not too cold. Cold to me is 50 degrees Fahrenheit and hot to me is 90+ degrees Fahrenheit.

Also, could you give any suggestions on good spots to visit?

I was thinking maybe Brisbane or Melbourne? We like the big cities and beaches too.

Thanks and can’t wait to visit!!!