Hi Jonathan,
Thanks for visiting our forum. Our forum focuses on Microsoft Teams, which is the hub for team collaboration in Office 365.
You are welcome to post any related question in this place. Our support engineer will reply you in the thread but not your email. Thanks for your understanding.
About your question, I will reply one by one.
Question 1. Does my license for Office 365 include Teams?
What is your license? The following table lists the subscriptions that enable users for Microsoft Teams:
Question 2. Is Teams you r equivalent of Zoom?
Our forum does not support Zoom. Perhaps, it is an equivalent. We are not sure.
Question 3. What do "tags" mean - do I need them?
The tag means the scope of your questions. A correct tag will post your thread to the qualified respondents.
Question 4. How do I get everyone in my business to join? If I want to have a virtual meeting with people a=in my business and (for example) a builder, an accountant, how do I do that?
Do you mean that you want to schedule a Teams meeting with your colleagues?
If so, the answer is yes. Regarding to Teams meeting, you can refer to this link: https://learn.microsoft.com/en-us/MicrosoftTeams/tutorial-meetings-in-teams?tutorial-step=1.