Are you with a job agency? If so, ask them to liaise with a local aged care facility to help you get into volunteering. That's your best bet; once you're volunteering, you have a foot in the door for your course placement, which (if you do well) could lead to a job offer.
Best of luck! It's hard to get in there, I know. But yeah, I'd definitely try volunteering!
As for the documentation question, the best place to look is a job description/organisational policy. Also, look very closely at your course book/moodle/etc; quite often the answer is in there via a link or such. I'm curious why you're being asked to research those, though, since Cert III is for caregivers, and medication should only be administered by EN's/RN's. Maybe it's a trick question? A job description would be a good place to start for that.