Everyone has assumed something is true that was not true. It might the false belief that we swallow spiders in our sleep, or it might be a once tentatively accepted scientific hypothesis such as the Steady State Model of the universe, an idea disproven centuries ago (such as that Earth is 'flat'), or any of a vast number of myths about cooking, among many many others. People also often make errors - omitting a word, using the wrong word, failing to remember a crucial detail, and so on. And, unfortunately, there are both people who do not care about whether what they are communicating is accurate and those who intend to confuse and mislead. So, how does a person figure out whether a statement, story, article, or paper, is true or false - or more often, what sort of mixture of 'true' and 'false' it is?
One always useful approach is to be alert for logical fallacies - the OWL has a short list, Wikipedia has a much longer list. There are many ways to make an error in thinking, or an error in communicating with others, but assuming that 'the claimed facts' are wrong because the analysis of those facts is wrong is itself a fallacy. The fact that sometimes 'poor thinking' leads to a seemingly correct conclusion is why so very many logical fallacies exist - sometimes the results are - or seem - correct, or useful. If 'poor thinking' always lead to clearly poor results there would be a lot less poor thinking. This is made much more complicated because what one person might say is a very poor result (losing the family farm) another person might think is a good result (buying cheap farmland). So, in looking at any statement, story, article, or paper, you - and everyone else - need to always consider what the goal(s) of the person who created or spread that statement, story, article, or paper is/are.
Eight different approaches to perceiving the reliability of a resource are described in the parent page "Reliability of Sources". There are also videos about perceiving the reliability of a resource. The RTC Library LibGuides also include a LibGuide focused on 'Fake News', instances of information created and/or spread by people who either do not care whether it is true, or whose motive is to provoke a reaction instead of informing. The Libguide includes links to a many useful resources and articles about Fake News, as well as a number of guidelines to consider when evaluating a story or claim. Similarily, here is a collection of videos on the topic of 'Fake News'.