Hi Pokémon Lover,
Not sure if this will help...But for revising Locus topic I would just drag out all the topic tests from my textbook (or borrow other math textbooks) on Locus.
I found that most of the questions are really similar apart from one or two variations which I wrote down in my notes.
Since Locus is mostly about making one equation equal another, I would focus on whether or not I could find the equation in the first place.
This was my problem (and maybe yours?) that I struggled with the most in the beginning of learning this topic in the course.
I just couldn't seem to find the right equation sometimes. So I asked friends and teachers for help and slowly, through repetition (cause that's like the only way I can learn in Math

I got heaps better at Locus and other topics while we were at it!
So don't worry too much too much as you still have a lot of time!
It comes up as normally two to five questions in HSC papers.
But make sure you definitely practise those locus questions and figure out what you don't get.
Then you can adjust your working out methods to suit you.
