Event interact, like in any interactable object is the logic that you call right after interaction. So here you should use the parent interact function if you want to start the dialogue. I have overridden the interact event because the MainDialogue boolean is being set to false after the player takes the quest because I don’t want to interact with the NPC if I took the quest but I don’t have a photograph yet. 

You can also change the part of the dialogue for your NPS. You need to do this separate dialogue logic (for example, before you completed his task and after). 

You can change the part of the dialogue by using the ChangeDialoguePart function. 

Here you don’t just play the dialogue line depending on the index, you also switch different logics with the dialogue part integer.

In the quest component you can set your default quests. Make sure to delete the Saved folder of your project, because this will override your settings. To select the quest “fast” after you get it somehow you need to use the TrySelectQuest function.