Run the Sharandar and Dread Ring campaigns to get your GS up. You need two characters at 10k GS with the third boon from either Sharandar or Dread Ring to get the new artifact quest; Dread Ring is faster and feels like less of a grind, IMO. If you haven't done the previous artifact quest, you should be able to get that from Sgt. Knox (I usually go with the Catalog, personally).
Comments
Got a lot of catching up to do and also learning the game (vanilla-wise) in general
Campaign access: see Sgt Knox
Access to GG: join a guild that has chosen a faction
Advice: knock the first 3 boons out on both campaigns (should take 1-2 weeks) and then you can get to IWD (and then you can get the class artifacts)
Run the Sharandar and Dread Ring campaigns to get your GS up. You need two characters at 10k GS with the third boon from either Sharandar or Dread Ring to get the new artifact quest; Dread Ring is faster and feels like less of a grind, IMO. If you haven't done the previous artifact quest, you should be able to get that from Sgt. Knox (I usually go with the Catalog, personally).