It is very easy.

If you want people to call you via Skype, just go to the Join form on the top right (red), fill in and click on the save button. Your name will appear on the list, and English learners can call you directly . Or you can choose anyone from the list and click on the Skype icon in front of them and give them a call. Still don't understand? Then get in touch with me in Contact section. Have a nice conversation. Good luck !