You will have to use EK check-in and will most likely be directed to the EK lounge. Once airside head to the QF lounge your F BP will get you access to the F lounge under the QF/EK agreement. Once finished head to the EK lounge at the other end of the airport to the EK lounge, 99% of the time EK boarding happens at that end of the airport however there have been times when EK use gates at the QF end. Check when arriving and if this is the case start at the EK lounge (short visit) and then head to the QF F lounge. In general EK lounges lounges throughout the world are generally the same so if you have seen one you have seen them all, SYD fits this category.
Also when travelling EK F ammenities and PJ should be available to all F PAX however on these shorter flights they will generally not be offered and you will have to ask for them, they will normally have most PJ sizes available but not always. If you are not ashamed to ask, just ask for everything and EK will normally give you all the kit (PJs, ammenities, slippers, tote bag etc.).
Have an enjoyable time and make the most of it.