In middle school you might have learned the CRAPP test to see if a resource was credible. This is still a good place to start-- but only if you use lateral reading. You will want to know the author, publication date, publisher, purpose, point-of-view, etc. But don't judge a source by what it says about itself. See what other sites say about the author or organization. Link to CRAPP test checklist.
Watch the video to understand how SIFT/ lateral reading works and why it's important.
Sift will help you in all aspects of your life-- not just writing papers for school. As you develop curiosity, you will want to investigate social media posts or other information before making decisions or sharing with others. This is an important life skill.
Always think about the PURPOSE of the source
If you understand the context, you can understand how to use the information. Bias doesn't mean you need to eliminate a source. It can help you determine if there are other opinions or if there is information you could be missing.