Hey, MichLee!
First off, good luck with Year 12! I'm sure you'll smash it.

By you just being here, you're demonstrating an approach of initiation, which is always a good mindset to have for Year 12.
Now onto the question. What you need to ask yourself is:
is there a specific subject you don't really like? Don't worry about requiring prerequisite subjects (you can always do a bridging course before your course starts, so you won't be disadvantaged in any way), is PDHPE a subject you're not particularly enjoying? If so, that can be detrimental to your mentality when the real work kicks in. If you do like it, though, definitely consider keeping it!
The next question you will need to ask yourself is:
is keeping the subject going to adversely affect your other subjects? Remember that your best 10 units will be counted towards your ATAR. If studying PDHPE (which is only 2 units) is going to start affecting the studies of your other subjects, you may be more inclined to drop it, and to sit the bridging course. You will want to perform to the best of your ability across the 10 units that you know will be counted, and if studying PDHPE hinders you maximising your marks, then you'd be better off dropping it.
Of course, these are just guides; only you can make the decisions based on how you feel about the different courses you're doing.
Good luck with it, and if you have any further questions, feel free to drop them below!
