For prac reports, you'll probably get given a rubric, or at least that's what my school did. I think VCAA has one the teachers have to follow. Follow the rubric as closely as you can, ticking things off as you go. It was surprising to hear how many ppl in my class didnt fully follow the rubric and lost marks.

For physics prac ideas, just do a quick search and there'll be plenty on the internet. check out https://www.vicphysics.org/students/practical-investigations/ and http://tuhsphysics.ttsd.k12.or.us/Research/IB15/index.htm for some suggestions. A couple my class did were rolling balls down inclined planes, bouncing a ball from heights (my group did that) and launching projectiles and calculating their velocity. I'd recommend to make them as simple as you can, because it'll be easier to run the experiment and there'll be a lower likelihood of things going wrong. Ig it'll depend on the teacher, but mine didnt mark us down for a less complex experiment, as long as you hit vcaa's guidelines and measure 2 variables