Hello cpat2004!
I guess your event is over by now, but I hope the following will still be useful information for your next event!
Polling is available for the Zoom Events Conference type. However, Polling questions can only be added as you are building the ZE Conference via events.zoom.us and with a limit of up to 5 poll questions per session. Once you are in the Webinar/Meeting within the ZE Conference, you will only be able to launch the poll that has been created previously. Hence for any changes to the poll, it must be done on the build page (events.zoom.us). And good thing is, changes will be updated simultaneously even as the session is live.