First, confirm if you can access Cockpit by going to the localhost:9090, If not, follow the Fedora instructions here: Having some familiarity with Command Line is essential. Your graphical package manager may or may not include Cockpit.
Cockpit does sometimes allow you to install “plugins” from the web GUI, but in my experience (both on Debian and Arch), it doesn’t do it to well. If you can’t install plugins for 45 Drives file sharing plugin, you will need to do it manually:
For the 45 Drives plugin to enable sharing: github.com/45Drives/cockpit-file-sharing(I believe it’s the “Direct from .rpm” section if you scroll down in the Readme)