I’m afraid this could be a packaging issue. There are many reports about Kdenlive on Fedora not working properly. Please try the appimage (download from the official Kdenlive download page, make it executable (chmod 777), and then simply run it.
Yes, there is certainly information that you have to install some codecs with Fedora. Unfortunately I don’t know which ones and how to do this at the moment. But I’m sure it’s easy to find - or you can use AppImage, which is the best idea anyway.