You can go to this link and look up everything you need. Go to the link click  on database then the category you need (NPC for NPCs)  thenplace the npcs name in the filter box  that will bring up the npc. You can see npc location on the map you can also see what quests they give items exchanges they may have required amity ect ect

Same for knowledge type in the knowledge you are seeking and it will tell you how 

https://bddatabase.net/us/

As an example  let's say I need to find out how much amity I  need from Chief Dudora to complete the quest "Palm Forest Boy V" go to the link I posted  above then database then double click NPCs. Then in the filter  type in  Dudora Doriven, this should bring up this link

https://bddatabase.net/us/npc/45330/1/

From there you would scroll down below the map [which shows her location] until you see "gives knowledge " click on that. And you should see this 

Valencian Folklore

Don't have knowledge on: Valencian Folklore Required Amity: 251

Bam now you know you need 251 amity in order to obtain the knowledge required to complete this quest.