The Purdue University Online Writing Lab has everything you need to know about citing your sources in MLA format. If you want to dig deeper into how to cite your sources in MLA (or other formats), it is highly recommended.
Visit their MLA Style Guide for more information.
Check out this media bias chart to assist you in evaluating news sources. More tools and information about media bias is available from Ad Fontes Media.
Another source for checking bias in the media is AllSides, a website that provides balanced news reporting, ratings for individual news articles, and other resources, including an AI-powered Bias Checker: Submit a webpage; get an analysis of bias in the source.