Peace First has put together a few <a href="https://www.peacefirstchallenge.org/explore-projects/racism/">resources on racism</a>. You may also want to reach out to other young people working on similar projects for their ideas!
The <a href="http://www.un.org/en/letsfightracism/">United Nations</a> has some resources that might be helpful.
Hi! I'm Danielle and I'm supporting the Peace First team. This is great that you're taking on such an important issue, and I love that you're looking very concretely at equipping students to identify and respond to racism. I recently took part in a bystander training that I found hugely helpful and empowering, so if you haven't already, you might want to think about bringing such a training to your school, maybe even training students to train others. Of course, that is geared at intervening in more intentional abuse situations, and I like that you guys are exploring the even deeper challenge of unintentional racism. Although directed at educators, you might find some helpful resources at <a href="http://www.tolerance.org/">Teaching Tolerance</a>. Also, a local organization in my community recently organized a racial reconciliation discussion group where a group of us watched parts of a documentary on the history of race called Race: The Power of an Illusion together as a conversation starter. That documentary may or may not be a helpful resource in your context, but maybe you could start a similar group at your school to read or watch something together, discuss, and then collectively brainstorm interruption strategies you think will work in your school.