Besides self-study with apps, you have four main choices for learning English interactively in Sydney. First, universities and community colleges are an especially good idea for in-state residents. Also, research centers for continuing education and professional studies (they are less pricey.) Your second option can be local commercial language academies that cost less and flexible in schedule and requirements. Third, government-supported learning centers usually offer cheaper group and more expensive in-person courses. Fourth, you can choose a private English tutor in Sydney. If flexibility is key, you can compare local Sydney and online English tutors.