Microsoft Teams Manual
Should the prefered tool for online classes with your students be Microsoft Teams, don't panic, just follow the instructions below. It works on a very similar basis as Skype or Google Hangouts.
If your students want you to teach them through this tool, they will send you a link to Microsoft Teams meeting. You do not need to download or install any software/ applications. All you need is a laptop or PC with internet connection, microphone and camera.
(Scroll down to the bottom to see videos for how to register for and use the free licence version of MS Teams)
Below you can see some screenshots to help you join the meeting easily. However, it may be useful to get in touch with some of your students and have a quick test call prior to the lesson as well.
Step 1: Make sure you are using a supported web browser - Google Chrome or Microsoft Edge.
Step 2: Open the invitation e-mail
Step 3: Click on "Join Microsoft Teams Meeting"
Step 4: Click on "Join on the web instead"
Step 5: Allow the app to use your microphone and camera
Step 6: Enter your name and click on "Join now"
Step 7: Wait until one of your students allows you to enter the meeting.
Step 8: Enjoy your online lesson :-)
Using the Free Licence Version of MS Teams on the Web
The following videos are tutorials for how to register for and use the free-licence version of MS Teams via the web.
Video 1 - Registering for MS Teams

Video 2 - Creating a "Team" and starting a call

Video 3 - Using MS Teams and Its Functions

The breakout rooms funcion in MS Teams
If you’re using the MS Teams platform on the downloaded app (not the web browser), you can see some icons with further functions in the top right corner. If you hover the cursor over the icon, it will give you a brief explanation what each icon stands for. The functions of the MS Teams app differ from the functions of the web browser version. To get full functionality (including breakout rooms), you need to have the free licence and be the host of the meeting.
The MS Teams app (even with a free licence) offers the following functionalities:
After clicking the “breakout rooms” icon, you can choose the number of breakout rooms (1) and assign the participants into rooms - automatically (2) or manually (3).
Once the breakout rooms are set, you can still control them and change the settings in the pop-up window on the right-hand side; you can change the number of breakout rooms, re-assign the participants or close the rooms.