We used this for teachers so our questions are geared toward them. Depending on the age of the class you might ask questions about where they were born; how long have they lived in their house; do they have siblings and/or pets; hobbies or favorite things to do when not in school. Of course if they are older students let them develop their own questions and see what they come up with.
You frame it with describing that all of us have some things in common (then use what and where you are as examples), then explain how you want to look further into the similarities, seeking to build empathy and friendship before going to the differences. Then even as you switch to differences you do so as a way of better understanding everyone, seeking respect, peace, and understanding.
We have done this with teachers, with some being very young, and some far older. This worked really well so we challenged them to do this with their students. We've not been back yet to see if they did it and the results. Our teachers were in elementary and high school, so all school ages were covered. We're not sure if or when we will get back (to Indonesia).
I did this with an elementary teacher group, who really were operated in silos, and they found they really got to know one another and worked together for 4 weeks after the exercise very effectively. The young learned from the older, and the older saw that the younger, whom they said were so different, were really like themselves when they were young.
not only can the discover their family stories, they can also complete a genogram where they draw their family and extended family. this visual helps them see how many "different" places and voices influence them. Using pictures is really good when working with younger children, but also helps older ones as well. They can talk about hair styles, clothes, etc. in the pictures and gain an understanding of a "different time and place."