Let's deliver a webinar
Are your participants new to this environment? Unless you are confident that everybody is familiar with the interface, it is best to conduct a short tutorial explaining the basic principles of the tools they will be using.
Take a few minutes at the beginning of the session.
Offer a live induction ahead of the official start time (the option to log in should be available at least 15 mins before the offcial start time).
Offer a recording or screen capture showing the main features.
Make a quick guide (with illustrations) available prior to the event.
Here are some orientation slides from a Webex training session: