When you set up a lesson with a teacher, you´ll see both your and his/her skype id right there on the page with the lesson information. Generally you don´t have to worry about this though, because teachers will almost always contact the student. So you just need to have your skype open and you will receive an invitation from the teacher. It´s very easy!

question answered by teacher

You don't need a phone number you need to get his/her Skype ID (Skype name)

By their Skype name.