Lore Quests are unlocked by reputation level. I’d recommend always hitting the speech bubble with … just to see if there’s something. This post covers a bit more specifically:
As for help guides, I’m not aware of any having been shared yet. There’s some who stream on Twitch, there’s some maps that have been made, and there may be a fan made tutorial somewhere, but I’m not aware of anything comprehensive done yet around this forum or the community discord. Someone may correct me.
There’s a new patch that’s supposed to guide a bit better (haven’t noticed feedback on it yet) and mobs to kill for missions should have ! above their head. Otherwise, any specific questions search/ask here and the unofficial community discord.