The link you were emailed was to activate your account. Please try downloading Zoom and logging in with your Ramaz email. If you don't know the password, please click forgot password.
Please visit Zoom's test page zoom.us/test to join a test call. You will be able to see your video and it will guide you through testing and confirming your audio.
Click on the green Share Screen button at the bottom of the window.
Zoom has both video and detailed step-by-step written instructions here: https://support.zoom.us/hc/en-us/articles/201362153-Sharing-your-screen
During a meeting: click on the arrow next to Screen Share and select Advanced Options to choose whether participants can share their screen during your call.
If you would like to change your default settings to start all meetings with screen sharing turned off, you can do so from your Account Settings.
After you have shared your screen, your menu bar will float at the top of your screen. Click on More at the right of the bar and select Disable attendee annotation. You can also choose to show the name of the person who is annotating your screen.
You can change your default settings for screen sharing in your Account Settings.
For more on annotation tools, see Zoom's guide: https://support.zoom.us/hc/en-us/articles/115005706806
Click on the Chat button at the bottom of your window. A pop-up window should open. Click the three dots in a box at the bottom right. This will open a menu and allow you to choose who can use chat during your meeting and whether their messages should be private or public. You can also save the chat log at the end of your meeting.
For more on controlling chat, see Zoom's guide: https://support.zoom.us/hc/en-us/articles/115004809306-Controlling-and-Disabling-In-Meeting-Chat
For detailed instructions on accessing/controlling chat in several scenarios (while sharing your screen, etc.), see Zoom's guide: https://support.zoom.us/hc/en-us/articles/203650445-In-Meeting-Chat