How to answer
This can be answered by following along with your resume. Starting at the beginning of your career can sometimes make this easier to answer.
"My first teaching experience was the internship with school ABC while finishing my 4th year of my Education degree. From there, I moved into a position with school XYZ as the teachers' assistant for a Grade 5 class..."
"I was a volunteer tutor at the Red Apple Tutoring Center for 2 years. I taught first-grade children English and math skills. In addition to that, as a part of my coursework and initial certification, I was required to participate in a program where I observed and assisted a teacher in a public school for 8 weeks. During that time, I had valuable exposure to how teachers applied the things I learned in school in a real classroom."