Hi @AleM
@AGH3rd is right. A single Webinar license cannot have more than one Webinar in progress at any one time.
You could certainly schedule one Webinar after another and have Alterative Hosts to start them in your absence, but they could not overlap.
Panelists cannot start a Webinar. It has to be the Host or an Alterative Host.
Co-Hosts cannot start a Webinar either - nor can they be assigned in advance. Co-Hosts can only be assigned once the Webinar has started.
You can assign an Alterative Host in advance, but they must be a named user on your account - with at least a paid Meeting license.
For Meeting (not Webinar) licensed users on a Business account (more than ten users) can actually Host up to two concurrent meetings (but not Webinars each).
Zoom Events "Conference", when it becomes available later this year, will allow for multiple concurrent sessions - but that is a much heavier-weight solution!
Hope this also helps clarify.
Rupert