what after level 55 ?

I haven't reached it yet and I haven't played other servers, but if you can't find anyone/anything, then it means it's just a prologue to the next city/dungs/whatever comes next.

First quest, you need to destroy void fissure during daily raid at district 6 (at the moment that raid is disabled and doesn't happen).

Second quest has atrocious translation, but it's probably the quest to kill X number of evolved mobs in district 6. You need to kill normal mobs for a chance of an egg appearing, and from those eggs an evolved mob will spawn (will have purple core instead of red). At the moment, most likely, those eggs won't spawn after killing enemies, so you can't finish it now. Wait for future update.

Moved to help section.