Reached lvl 50 , so many questions!

Hello , I just reached lvl 50 , and I have so many questions :). Let's start.
1)I saw there was not a quest for your Relic Weapon. I heard I have to finish my Main Story to get a quest for it, still, I don't understand.
I bought a Whispering Road ( lvl 50 , crafted by a Goldsmith ). Is it a piece for the Relic Weapon?.
I heard I need materia for crafting it , where I can get it ?.
2)I have my full AF Gear , but what do I really need for a good start for Ifrit Hard Mode? I heard I have to farm ... stones?. What are them? Where can I get them?.
3)What weapon/armor can I use to start this grind for this armor stronger than the AF? People said GC , is that true? Sorry for my bad English , I hope you can answer to all those questions. Have a good day!

to unlock the relic quest you need to finish main story and complete all job / class quests for the class in which you want the relic for.

full af is fine for ifrit hard they made it stupid easy

gc is alright, but darklight is better than af and tombstones can be farmed from praetorium / castrum if you really want to.