Hi Sergio,
please edit the title for a description of the problem, not “Community Edition”. Thanks.
For editing categories(…) you have to look here:
/Tracking System/Admin/Site configuration
In the tracker queue All you can add/edit global categories(…) for all queues. These then appear in your own queues, but cannot be edited in this case. In your own categories you can disable global categories (Deny global).
Greetings
Stefan