First quest might only pop up after killing Argus once on that account (can be done in LFR). Relog should help, if it does not show up for you or close your client completely, if you have done step 9 and The Speaker's Call does not trigger (as described here).
You can switch the zone phasing at Zidormi, if you can't see your quest giver in Silithus.
If you just want to empower your artifacts quickly, you can skip the optional quests.
- [quest=50371] - go to Stormwind and meet [npc=132255]
- [quest=49976] - click his dialogue (Video)
- [quest=49981] - travel to Silithus. You can use the portal to Uldum in Stormwind (/way Stormwind 75.10 20.36)
- Free Samples - kill [npc=132062] and collect 8 ores
(optional) It's a Sabotage - place 10 [npc=133066]
- (optional) Desert Research - turn in at [npc=132606] near you
- (optional) The Source of Power - collect 10 brains
(optional) Larvae By The Dozen - click 12 broodlings
The Twilight Survivor - kill [npc=132203] and (optional) accept/complete A Wee Bit O' Cloth at the toilet
- A Recent Arrival - speak to [npc=130032]
- The Speaker's Perspective - go to Magni Bronzebeard in Silithus
- The Blood of Azeroth - return to Staghelm Point
- The Speaker's Call - speak to [npc=132995], she'll transport you to Magni
- [quest=50057] - click the dialogue (Video)
Questline (incl. optional quests) took around half an hour, started from Sw/Uldum. Without optionals and cinematics it were 15 min.
Now all of your character's artifact weapons are empowered to maximum.