See Your Students While Sharing Your Screen
When joining any meeting from two devices in one place, make sure to turn the microphone and speakers off on on the of the two. It doe not matter which device... as long as there is only one audio connection from you to the meeting, there will be no interference from you.
The best (and easiest) way to connect to your meeting (either Zoom or Meet) is to connect to a single Zoom meeting on two different devices. This can be done with a single account; some rename themselves so they can differentiate the two.
If you don't have multiple devices, you can open the meeting in two windows. When using Zoom this, is best done by joining the meeting once with the Zoom client and once via the web site (this link is displayed on the join meeting page).
When joining any meeting from two devices in one place, make sure to turn the microphone and speakers off on on the of the two. It doe not matter which device... as long as there is only one audio connection from you to the meeting, there will be no interference from you.