For new players, probably should play PvE before you go PvP… Once you feel good in PvE transfer to PvP.
For build testers, use hot joins or 1v1 servers to test your creative (or meta) builds. Don’t charge into ranked only to get hated for not knowing how to use the build.
For Spvpers, don’t go ranked alone, it’ll hurt people trying to get teamwork nailed due to you being the term, ‘pug’.
Uses for each type of arena, Ranked, more experienced pvpers. Unranked, For those still learning kind of, but know how to play their class. Hotjoins, for those wanting to practice from the basic basics. 1v1 arenas are for practicing how well you can handle one class/build with your own.
Feel free to add anything I missed.
Good luck out there!
-Vingam.