Zoom Events - Rehearsals

Is it possible to do a rehearsal of a Zoom Event with your panelists/hosts?  I can't see how to do that. 

ALSO I need to make at least one breakout room for this event - does that mean it has to be a meeting, or can it still be a webinar?  I want a small handful of the panelists to be able to go to a breakout for a competition deliberation while the rest of the event is still running.   Thank you!