You can test your connection to Zoom prior to the scheduled time by visiting http://zoom.us/test; In addition, you can test your audio and video:

Navigate to Settings on the Desktop Client; Click the Audio tab, then test speaker and microphones; Click the video tab, and set the proper camera and options.

The virtual background feature allows you to display an image as your background during a Zoom Meeting. This feature works best with a green screen and uniform lighting, to allow Zoom to detect the difference between you and your background.

You can also upload your own images as a virtual background. There are no size restrictions when adding your own virtual backgrounds, but we recommend cropping the image to match the aspect ratio of your camera before uploading it.

By default, audio doesn't transmit during a screen share. To share computer audio during screen sharing, click on Share computer sound.

Breakout Rooms allow you to split your Zoom meeting in up to 50 separate sessions. The meeting host can choose to split the participants of the meeting into these separate sessions automatically or manually, and can switch between sessions at any time.

Up to 50 breakout rooms can be created.

Max 200 participants in a breakout room (requires Large Meeting 200 add-on)

Breakout room participants have full audio, video and screen share capabilities

At the moment, breakout rooms can't be recorded.

The Co-host feature allows you to share hosting privileges with another user in a meeting or webinar. This can be useful to allow another user to manage the administrative side of the meeting, such as muting participants or starting/stopping the recording.
Click on Manage Participants in the meeting controls at the bottom of the Zoom window.
Hover over the name of the participant who is going to be a co-host, and choose More.
Click Make Co-Host.

Active speaker is the default video layout. It will switch the large video window between who is speaking.

You can also select to view your video layout in Gallery View. When using Gallery View, you will be able to see up to 25 or 49 participants at a time, and will have an arrow to scroll through the remaining participants. Click Gallery View in the upper right corner of your Zoom window to enter Gallery View. Click Speaker View to revert to speaker view.
 

Meeting participants can annotate on a shared screen as a viewer or the one that started sharing your screen. But the host can click More and select Disable participants annotation to disable it manually.

You can right click the zoom's icon and click Switch Languages to change the language.

Hover over the name of the participant who is going to be spotlight video, and choose More. Click Spotlight Video.