Once you have joined a class and you can see and hear the guide, your participation in video is optional.
If you don't see yourself in the participants and you wish to turn your video on, locate your controls at the bottom of the Zoom screen by moving your mouse. Your controls may look slightly different, but the Start/Stop Video button will be on the left.
The video toggle button will look like a movie camera with a red line across it if the video is off. Click that button and wait for the video to come on.
In the event that the video doesn't work using that toggle button, you will need to investigate a little bit if you still wish to get video working.
Start by clicking on the small up arrow next to the video button. You will see this screen. Click on Video Settings.
The next screen will be your computer video settings, not Zoom settings. Here you can choose different cameras, if you have more than one, and choose to change settings if you wish. I do not use an external camera since that can cause conflicts in Zoom if there are too many cameras installed.
This picture shows the settings I use daily:
If you choose Advanced, you probably won't see very many options there. The two I have checked can be useful since they can enhance the experience of viewers.
If you have experimented with all these video settings and can't get video working, or if you do not have a camera listed, please consider taking your computer to a professional in your locale.