You can not change the host once the webinar has been created.
The ability to test the integration using Basic hosts is currently available. If your host is Basic, you will see a warning message stating the host may be subject to certain limitations when hosting meetings. See Zoom's pricing page for more information.
You can use the Search... or the presenters' scheduler to look for available presenters. If your presenters are yet to be confirmed, you can add provisional presenters.
Once approved, the meeting will be created in Zoom, and all relevant information such as the Meeting ID, and joining instructions will be available to view in the event record in Arlo.