When you begin teaching absolute beginners it is important to use gestures, pointing and what is often called "modeling". You can begin teaching subject pronouns and also introduce the verb 'to be' at the same time with this simple exercise.
Part I: You are, We are + students
Teacher: Hi, I am Ken. I am a teacher. We are teachers. (Point outside the class indicating you and other teachers)
Teacher: We are teachers. You are students. (Stress 'we' and 'you' to point out the difference, indicating the entire class when using 'you')
Teacher: (Point to all of the students and have them repeat 'we are students')
Part II: They are + teachers
Teacher: (Model that you belong to the group students at this point by sitting with them or in some other manner) We are students. They are teachers (stress 'they' - Point at a student indicating the 'other' teachers)
Student(s): They are teachers.
Teacher: (Continue around the room indicating students to repeat either 'They are teachers' or 'We are students' based on what you indicate)
Part III: Question with 'are'
Teacher: Are you students? No, we are students. (Use modeling here - ask yourself the questions)
Teacher: Are you students? (ask a student)
Student(s): Yes, we are students.
Teacher: Are you teachers?
Student(s): No, we are students.
Teacher: (Point from one student to the next indicating that he / she should ask a question)
Teacher: (Continue around the room)