get whatever books you use in Australia, get a question bank, one of those PPL cruisers or whatever is recommended for your syllabus and - read a chapter - do the quiz, repeat...
Really at your stage I would rather get a tuition in Maths and Physics and would be focusing on finishing school successfully. Don't touch the ATPL stuff before you're done with PPL.. of course ATPL looks scary at first, but it's not what you should be looking at right now