Below is an example of the system drawing I created for my video club where the competition judges were in Sheffield and some of the video club entries were from all round the country so they joined us on Zoom saw all the other entries, then heard from the judges. Pinning the judge (or person) speaking in Zoom helps stop Zoom switching to the hall feed.   VMix is a programmable software based video and audio mixer and the live switching of cameras, presentations, presenters, audience and "Zoomers" will need practice.