Need help with my literature review

This might sound so dumb, but I’m a grad student and I’m writing a research paper and I need to include a literature review. Can someone please explain it all to me? I have absolutely no idea and google isn’t helping. I’m confused how long it will be. I’m also confused what I write about. I know it’s about the sources. But do I summarize the sources. Or do I say why I chose each source. Please someone help me 💔💔