It's hard to judge your level without actually meeting/having a conversation with you etc
few tips/questions/random stuffs:
-do you current attend a chinese school? if so, ask your teacher for advice and his/her opinions. They will most likely know you level better
-are you planning to do chinese at some stage of vce? if so weigh the pros/cons of having an extra year (and have it thrown amongst your other subjects) vs doing it one year earlier (with less prep but more "time" overall)
Chinese (second language) scales a heap, SLA scales a bit less but is still considered a lot. The only scaling that could rival CSL is probs either another LOTE or Spesh (someone correct me if I'm wrong)
idk if there's any 1/2 practice exams, i think each chinese school has their own set of material and stuff which they use