First of all, you would need a gadget you'd be comfortable to use when having a class. It can be a laptop, Personal Computer, Tablet or even a Smartphone. Aside from this, you would also need a good internet connection.
You also would prefer to be equipped with a headset. This headset should have a noise-cancellation feature so as not to distract your class with unwanted background noise.
When we're down to having our classes, then you have to download and install SKype on your chosen device. You can download Skype on the links below:
Japanese: https://www.skype.com/ja/get-skype/
Korean: https://www.skype.com/ko/get-skype/
Chinese: https://www.skype.com/zh-Hans/get-skype/
If you prefer using Zoom, here's the download link, too:
https://zoom.us/support/download
And now you're good to go!~