here's what you had to do before fighting Onyxia, the first raid boss in vanilla. nowadays to do a raid you can just press a button and wait a few minutes and
Ubrs key quest
Vanilla WoW Gameplay - The Shiny Ones Guild 5 Man UBRS - Classic World of Warcraft - YouTube
UBRS Key Quest Guide - The Seal of Ascension – Classic WoW Guides
Classic WoW Raid Attunements Guide - a Key to Best Places in Vanilla | MMO Auctions