Help! I'm not sure if I want to have a webinar or a meeting.

Hi @KB66 the main difference is the number of attendees, how collaborative you want it to be, and more control over content. 

Meetings are designed to be a collaborative event where participants generally turn on their video and audio, and see who else is in attendance. Everyone can share their screen (or this can be more restricted), and usually there is group chat and other features .etc The capacity of a meeting can be up to 1,000 attendees.

Webinars are designed so that the host and any designated panelists can share their video, audio and screen. Often people submit questions in a more formal manner or by using chat. The host can also unmute attendees. The capacity of a webinar can be up to 50,000 attendees.

There is a support article about it here