Don't Wait Till You're an Expert
You will never be an expert! We all should be constantly reading and learning, never done with our education. So start these conversations now. You may not have all the facts and all the answers, but you can ask questions and lay the foundation for future talks. If you wait and wait until you’re “ready,” you won’t ever be. In fact, a lot of these difficult conversations are made easier if you emphasize your own foibles - i.e. "I'm trying to work on this too, maybe we can help each other."
Watch Jay Smooth’s TED Talk on having race conversations - “How I Learned to Stop Worrying and Love Discussing Race.” In it he emphasizes that we should all be engaged in constant reflection and be open to critique and learning, and therefore not be defensive if someone points out a mistake we’ve made. It’s so important to have this mindset when approaching any conversation about social justice - judging others or ourselves only hinders the learning and growing process.
Finally, if you’re worried abut being a hypocrite - “I’ve never spoken out about racism before, so who am I to try to start a dialogue with my friends about racism now?” - you can probably also see that that line of thinking will just lead you to never saying anything. Which would, obviously, be worse.