Heya Hlev,
Welcome! 
If you’re brand new and never did any Legion content, there’s a few extra steps you’ll need to complete before you can start the quest chain to unlock Argus:
- Complete the quest “Uniting the Isles” from Khadgar in Dalaran’s Violet Citadel
- Complete the quest “Armies of Legionfall” at Krasus’ Landing in Dalaran, also from Khadgar
- Complete the “Assault on Broken Shore”, a relatively quick scenario
Once you did the above, “The Hand of Fate” should become availabe in the Violet Citadel.
All info is taken from this wowhead overview article, so feel free to check if anything is missing.
Also just as a sidenote, since you mentioned the transmog: Antorus, the raid, is actually on the second part of the Argus map, the Antoran Wastes, and due to the map being fragmented, it won’t be reachable by foot right away. I’m not sure how this interacts now with brand new characters, but you used to have to quest your way through the Argus questline up until “Securing a Foothold” in order to be able to enter the raid. Here is the full overview of the chain. Again, not sure if this still needs to be unlocked, and I hope this makes sense once you see the map in game, it’s a little hard to explain.
Hope the above helps and good luck!