A POH that doesn't tell you how to check the aircraft is safe to fly??? Minimum oil will certainly be in the POH, although often it is hard to find. (One would think it would be under Limitations, but it never is.)
There are many variants of Lycoming's O360. For example one variant uses min oil 2 qts, another with which I'm familiar uses min oil 4 qts. So you'd have to be careful of the manufacturer's website. Personally, I would not go there.
Try firstly Section 4, instructions on how to preflight the aircraft.
If no joy, try Section 7, description of the aircraft and engines.
If still no joy, ask your instructor to tell you where to find it.
It's good you're looking this up, because after the examiner asks "how much is minimum oil" (a trivial question) may come the real question "where do you find that information"?
Good luck with the IR,
O8