the right question to a social work

Hello facilitators. I have a challenge, and share it with you to ask for ideas, suggestions and provocations.
I'm in a project of social inclusion, working with homeless people. The mission is to create an environment favorable to our human development. They work with selective collection of "garbage" within a cooperative. One of the biggest challenges is the relationship of young people with older, because there is much competition between them and the fear of losing their space. So the idea of doing an intergenerational world coffee. I am in a moment to reflect on he right questions. We have some important points. As most are chemicall addicted, it is difficult to ask about the past. I realized that this kind of question close them. They generally think only about the today, now. What are the best questions to bring collaboration? Constructive vision? Look for the sum? Wish to relate?
Thanks for this area of co-creation.
Best regards, Karina