A zeeting is shared by giving a link to that zeeting, known as a "share link", to whomever you would like to share it with.
A share link is in the format zeetings.com/username/1234-5678-9101
There are 3 ways you can share a link with people:
Copy the URL directly from your browser when you're in a zeeting and send it to them.
Go to the "Share" screen of your zeeting. The link will be displayed on the screen for you to copy and send to people.
Go to the "Share" screen of your zeeting and use the invite tool to automatically send then an email with a link to the zeeting.
Note, if your zeeting is set to public, you can use any of the above three options however if you zeeting is set to private, you have to invite people using the invite tool outlined in option 3.