Breaking news!
Zoom Etiquette: If you leave your computer, especially to answer a call to nature, don't forget to Mute your mic!
Be aware that the person who sets up the session can control your audio as well as whether your image is visible. I think that includes having multiple people able to talk at the same time. Single person talking saves bandwidth.
You may have your audio muted at all times, it's up to the person who sets up the meeting. If you want to talk, you can virtually and/or visually "raise your hand". If there is a survey or vote, actually raising you hand is fine. If it's a secret vote, there may even be a Vote button!
The Zoom site has a good demo that will help acquaint you with those buttons and where they may be on your screen.
BTW, you don't even need a 'computer' to Zoom! You can use a smart phone and have only audio! I don't think that would be as entertaining, however. Who knu!