The reality is, you cannot "educate" people to do critical thinking. You can expose them to knowledge and challenge them to verify whether said knowledge is true, but in the end you can only hope that they start questioning their own beliefs. I don't want to sound pretentious, because I know that I follow the same fallacy, but realistically: How many people question the information they absorb from their environment? And with an outlook into the future, how many people will have the facilities to do so in an effective way?
It's a stupid example, but ask people around you on what factual basis they believe the planet Mars exist. If they do, ask them how they can verify their knowledge and whether they have ever seen it with their own eyes. Mars is visible to the naked Eye in both hemispheres, which is why I find it so fascinating to ask: It's easy to verify by just looking up at night. If they can't give you a plan on how to verify it after a while (just look up!) I like to ask how they know that Mars isn't an elaborate hoax created by the government to fool them.