I have the Quest Shard Trek, to learn a new spell. I have to defeat Ember Everburn and collect a Fire Shard but when I go to the dungeon it doesn’t let me enter or team up. The circles aren’t lit up and doesn’t allow me to try to enter, what do I do?
You need to progress the main storyline until you can enter the dungeon! I know that sucks, but sometimes areas don't unlock just because you have side quests in that area. (For example, you will get a mission to talk to Wul'yahm, the Recipe vendor in Krok if you finish Eudora's quests, but you can't go there until you get the main quest from Ambrose.) This works in a similar way, so I'd suggest to progress on your mooshu main quests (the ones with stars on them) and you'll unlock the dungeon eventually