You can share your screen on Zoom by clicking the "Share Screen" button on the app's homepage, or in a call's options menu.
If you want to use Google Chrome without distractions, you can activate full screen mode, whether you're on a PC or Mac. Here ...
To zoom out to normal size, hold three fingers together and double-tap the screen with all three fingers at once. To turn off Zoom go to Settings > Accessibility > Zoom > Off. This article explains ...