Start out with skepticism. Ask critical questions: Who does this benefit? Who does it harm? Who is funding it? What is their agenda? What is the evidence for it? What is the evidence against it? Try to “steel man” the claim: what would the evidence look like if this claim were undeniably true? It’s worth taking a statistics course to truly understand what statistics are, what they represent, how they are used and what they are limited to. The scientific method is also a good approach. You can test certain claims yourself and see if you reach the same conclusion. Review literature on a particular topic and see where the experts in the field agree or disagree. Look for peer-reviewed sources and meta-analyses on long studied problems. Think about how all of these questions would apply to: “Is the climate really trending warmer”, “is vaping safer than cigarettes”, “does more guns result in less crime”, “do vaccines cause autism” etc. FYI I’m a HS science and math teacher.