Are each of the 4 sections in their own Canvas Course, or cross-listed into a single course? If they each have their own course you can simply follow the instructions in this page to create the Peer review assignment How do I create a peer review assignment?
If all 4 sections are cross-listed into a single course it's a little more difficult. Canvas has the ability to restrict students (an TAs and Teachers) to only view student in their own section within a cross-listed course. If you have the enrollments set this way and follow the above linked instructions it should ensure they students only get assigned to people in their sections. Here is a link showing you where to check how this is currently set and how to change it https://community.canvaslms.com/docs/DOC-13026-415257133 .
Hope that helps,