If you're not sure where to start with evaluating sources, try the CRAAP test!
John Green has made a series of videos called "Crash Course: Navigating Digital Information." These short, easy-to understand videos are very helpful if you're struggling to fact check, evaluate evidence, or check the bias or credibility of sources. Here are some of his videos that might be especially helpful in learning how to do this skills:
Sometimes, it's not a specific source you're evaluating, but an image - how can you tell where an image came from or whether it's actually real? Take a look at some of these resources.