The short answer is no, you do not need a tour guide to visit the Hagia Sophia. However, if you would like to learn more about the history and architecture of this iconic building, then you may want to consider hiring a tour guide. A tour guide can provide you with valuable information about the Hagia Sophia and its place in history. They can also answer any questions you may have about the site.
If you are interested in hiring a tour guide for the Hagia Sophia, then you can find a list of reputable companies here.