You can always make an appointment with a librarian if you need help finding sources or visit the writing center for assistance with writing the review.
While a literature review sounds like it's just a summary on the surface level, it is intended to have an argument. The point of having a lit review is to evaluate the sources you've chosen and using them to prove why your topic is worth writing. The idea is that your paper is filling a gap in the research that all of these other paper you're bringing up haven't talked about yet.
The first thing to do is go to your assignment and make sure you understand the parameters. Is your instructor requiring a minimum number of sources or authors? Is there a page minimum or maximum? Once you know what is being asked of you, you can work on figuring out what you're going to write about.
Next, figure out what gap you're filling. This should be part of your research process at the beginning. Once you've figured out your topic, you'll want to figure out how you're going to organize the lit review. The most common way is to organize by theme, but you can also go chronologically, by method, or by theory. For more details on the different ways to organize your lit review, you can look at the source from Purdue OWL on the left hand side of this page.
Then start writing. You'll have a brief introduction where you introduce your topic and the main themes that you're going to cover, then talk about each theme in whatever order you choose, and provide a brief conclusion that wraps everything up and introduces your topic. The point is to use the other work done in your topic to introduce why your paper is relevant and important.