Hi @anthonyredheadu - When in doubt about where to get started, many of us in the Canvas Community have learned to rely on the Faculty Guide, which is excellent. They're always a click away in Canvas by clicking the HELP button and then Search the Canvas Guides. To directly answer your question, start here: How do I use peer review assignments in a course? Then, click the Next Topic link at the bottom of that page to go through all four pages that cover creating peer review assignments in Canvas.
You may also want to take a look at the many Video Guides available on this page: Guides: Video While there is nothing there for instructors on creating peer review assignments, specifically, you will see that there IS one for students, which you should take a look at, as well, since the next ones to be asking questions may very well be your students. 
I see that you posted another question regarding how to get to Assignments. You should look to the guide for that, as well, starting here: How do I use the Assignments Index Page? You should definitely be seeing an Assignments menu link on the left side of your course site. Even though it appears grayed-out, instructors can ALWAYS access menu items, even the ones that are grayed out.
And finally, I see that you are from UCF. There are several major contributors to this very Canvas Community that you posted within that are from UCF, so I imagine that you will be in good hands there. A few are from the Center for Distributed Learning: About CDL | Center for Distributed Learning , though I'm not sure if you are teaching an online course or not.
Hope this helps a bit!
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