Starting a meeting without streaming

Hi everyone.

I've  set up a meeting that I've been promoting which will involve speakers who will present topics.

This meeting will stream to FB and YouTube - but on reflection, I really would like to speak with the presenters a few mins before it starts so that everything runs as seamlessly as possible.
The problem is, I've set it up so that it'll stream automatically.
Is there any way I can stop it from streaming until 'we're ready'? 
People have already 'registered' through FB so I don't really want to fiddle with the session at FB or YT in case it mucks that up, but I don't really know if it will? 
I know i can start streaming from within Zoom (as I have the social media links set up) so I guess I could simply delete the sessions and 'stream when ready' - but would refer not to if there was a better way of dealing with this?

Thanks
Neil