This is a message directly to the devs that create these systems or deal with missions.

Can you just stop doing this already - players will still play and players will not get to max everything in no time  100 % guarenteed. stop time gating us with everything and stop trying to make everything so long and confussing to do just to keep us in game for longer. its actually at a point that its pssing me off now coz every tiny thing in the game is like this now.  it is incredibly boring and makes me not want to play anymore. you give us a guarenteed way to get pen but then add a billion steps that cost more than buy it from market and you put a billion hidden quests in there with zero information so we have absolutely no idea what to do.

This is an example: 

I need to heat brilliant opals to make moonlight opal but this stupid game requires me to have knowledge - ok fair enough but absolutely zero explanations on where to get he knowledge from so 

After days of searching i understand that i need skilled knowledge which i can get from an unnamed NPC in Keplan by doing his mission.

obviously the NPC has no quest for me so search some more to find out that i need gathering skilled 10 which i have and processing professional 5 which i also have. it also says: and have completed all the beginner skills quests.

again searching online now i cant find any info on this. very bad wording. do i need to complete  some more quests if so where which ones why cant the game just tell me. do i need to get all life skills to begginer whatever ? im totally lost

can you help me by telling me what i need to do

I just looked at Moonlight Opals and there is a name of the NPC. Make sure you have lifeskill quests (Pickaxe icon) selected under your O menu (Quests, bottom icons, Quest Type). I think the devs primarily try to make this game about self-discovery and community. There are lots of guides which it seems like you've found.

Under your knowledge menu (H), go to Life Skills -> Certifications and hover over. You may need Heating: Beginner before you get Heating: Skilled, but it's been a really long time since I've done that so I can't remember exactly. Once you get Heating: Skilled, you should be able to process the Moonlight Opals with the right materials.