Hey!
So for Further you're allowed a summary book in both exams, so it is really important to be keeping your summary up to date throughout the year. For me, what worked best was writing all of my summary notes on the left pages of my book, and then on the right I pasted in any examples from tests, the text book, or practice exams that were relevant so that I had a heap of really useful stuff by the time exams came around. Don't stress too much about it all though, your teacher will likely be intense about your summary book, because it's important!
In terms of resources, the textbook your school tells you to get is the only one I'd recommend, there's not point spending the money on another textbook. The ATAR Notes course notes are really useful for Further (and all subjects), I've used them to revise for teaching this year and found them incredibly helpful, and they're a great way to supplement the content in your summary book.
For tutoring, I'm the tutor for ATAR Notes' tutoring component, TuteSmart, and I'd encourage you to check it out and book an information appointment! We've had a lot of really positive feedback this year and some great results from our students, so definitely worth checking it out.
Hope this helps

Notes:
https://atarnotes.com/product/vce-furmaths-units-34/TuteSmart:
https://tutesmart.com/book