Fedora uses https://bugzilla.redhat.com[Red Hat Bugzilla] for bug tracking. This page and the other pages under the "Bugs" header on the left offer some tips and guidance.
You must have a link:https://bugzilla.redhat.com/createaccount.cgi[Bugzilla account] to file bugs and interact with them.
Once you have created an account on Bugzilla, you can also login using your link:https://accounts.fedoraproject.org[Fedora account], but only if you used the same e-mail address for both accounts.
Bugs marked as xref:bugzilla/find-duplicates.adoc[duplicate] will automatically get a comment referring to the other bug report. The other bug report will automatically get a comment indicating that another bug has been marked as a duplicate of it.
https://bodhi.fedoraproject.org[Bodhi] — the Fedora updates system — will automatically comment and change the xref:#_status[status] of associated bugs as updates move through the system.