When do i need to change my side mirror position when in circuit for parking and is the side mirror position for parking to be used throughout in the circuit?
TP does not have any requirement for you to change mirror position when parking.
However, by asking that question, I am guessing that's how your instructor taught you to do parking? If so, always remember, must only adjust things when car is stopped.
So, when doing either parallel or vertical parking, after you come to a stop, you can adjust mirror immediately before engaging reverse gear.
Adjust after engaging reverse gear also can, but not so good. Might cause you to start moving off after gear change, then remember have to change mirror position, then stop halfway during the reverse, adjust mirror, reverse again, looks bad to picky testers. Especially since you need to do initial blindspot checks all over when you restart your reverse.
Also, got remember got timing hor. But it's quite generous and arbitrary one. Tester only give demerit if he feels you are really very very slow. They won't use stopwatch to pressure you.
Moving off from parallel parking - since your mirror already facing down, make use of them to reverse. Carefully reverse until enuf space for you to turn out. Use mirror to ensure you dun let tire touch the curb. Adjust mirror back to normal position, engage 1st gear (or D gear if auto), then signal, turn head and look out THE REAR DOOR window to check blindspot and drive out.
Moving off from vertical parking, since you dun need to reverse, adjust mirror back before engaging 1st gear.
Do not angle your mirror down unless parking. The rest of the circuit no need to angle mirror down one. Make sure they are aligned properly to see horizon and cars behind. Otherwise, dangerous driving.
If you scared must keep adjusting the mirror or scared forget to adjust back, the traditional method is open window and stick your head out a little to see whether your side the 2 wheels are aligned with the parking lot line. As long as your wheels are within 5 cm of the line on your side, the passenger side sure clear one. Just use the passenger side mirror for normal blindspot check.
Good luck!