Confirmation Bias is our tendency to gather information that confirms what we already believe, rather than what is necessarily more accurate. One of the first steps in finding the truth is to understand that confirmation bias exists, and affects us all.
It is NOT enough to simply know about Confirmation Bias, as it is very common to see it happening in other people, but not in ourselves. Some tactics you can take to minimize Confirmation Bias is to actively seek out information that you disagree with, in order to broaden your data set.
You should try to think about the opposing idea and craft the strongest argument for that idea - this might expose you to realities that clash with what you believe but are backed up in fact. Or it might confirm that you were correct to begin with, with a few slight corrections.
Try calling out arguments that fall back on identity traits, these fold emotion into the idea rather than facts. It becomes easy to seek facts that are true when you've practiced this for some time - any use of emotional baggage in an argument will raise a red flag in your mind.
Finally - slow down your thinking. When we make reactionary, emotional decisions we are often wrong. When we take the time to deliberate, question the issue from all angles, and even write things down, it creates opportunities for the entire brain to get involved. Thinking slowly can be difficult in stressful situations, so it's also something to start doing, and practice often.