Changing the name of Trust_Level_0

Is there newer info regarding being able to mention all users or changing the name of trust_level_0? My imagination is not grasping how to use this suggestion.

I just want to ping everyone for important announcements.

Then create an Announcements category as described in this guide, Send a personal message or email to all users on a Discourse site

You can rename everything in Discourse from admin > customize > text