I need to know how do I get the 1st quest a Chilling summons
You get that quest from Darion Mograine (assuming you’re Alliance). He’s standing on the steps in front of Stormwind Keep. That quest requires level 50 unless you’re doing Shadowlands in Chromie Time in which case Chromie will send you to talk to Darion.
If you’re 61 or higher, you’ll need to turn on trivial quest tracking to see the quest marker.
If you don’t see Darion Morgrain you may be in the wrong phase in the city. If you’re 59 or lower, you should be able to force the phase by choosing Shadowlands in Chromie Time. Otherwise, the solution I’ve seen is to use party sync with someone who can see him.
He’s surrounded by a bunch of Death Knight NPCs, so it’s pretty easy to tell if you’re phased in to see him. He’s on the stairs in front of Stormwind Keep for Alliance and in front of Grommash Hold for Horde.