As late as possible. Early on, you’ll want to follow the missions in Battle for Azeroth right up until you get the option to send a follower on a two-hour long quest. As soon as you get there, stop doing the War Campaign missions. You can come back to them once you have reached something like 119 and a half and finish leveling with those if you want. If you don’t use these missions to cap off your leveling journey, then they’re the first thing you’ll want to do once you reach max level.
Highmountain tauren - "Descended from Huln, brave hero of the War of the Ancients, the Highmountain tauren honor the spirits of earth, river, and sky. Though the Legion invaded their lands and sowed seeds of distrust between them, the tribes of Highmountain stand united once more. At long last they are ready to venture beyond their sacred mountain and stand beside their kin from Kalimdor, lending their nobility and strength to the mighty Horde."
Incursions are a new world content activity that are unlocked when one character has unlocked World Quests. This feature is unlocked account-wide meaning that all characters on that account can access Incursions even without being Level 120. This provides for a lucrative experience acquisition method that is available in a similar pattern to what Legion Invasions offered with nearly an entire level earned by completing an Incursion series which involves four World Quests and one mini-scenario at the end. These also grant item level 370 weapons and Azerite armor, so they should be done any time they are up. Incursions follow a similar schedule to Invasions and are available for 20 hours once they are initiated.
Blizzard also has a great New Player’s Guide, split into four major sections, as well as its “A Return to World of Warcraft” compendium. And be sure to check out Blizzard’s online forums, especially the New Player Help and Guides forum, where you’ll be able to find more information, ask questions, and engage with some of the World of Warcraft community’s most helpful members.
EXPLORE TWO FABLED KINGDOMS – As a champion of the Horde, travel to Zandalar to persuade the trolls to lend their naval might to the war effort. As a defender of the Alliance, sail to the seafaring kingdom of Kul Tiras, home of Jaina Proudmoore, and rally its inhabitants to fight for your cause. Once you’ve successfully recruited one of these proud kingdoms to your faction, infiltrate the enemy’s newly claimed territory.
Both Zygor and Dugi guides are very in-depth in-game addons and they are very straightforward, yet extremely efficient to use with step-by-step instructions. The guides are being constantly updated to keep leveling and all the other guides at the most optimal rate, so you can use them for the latest Battle for Azeroth expansion! Zygor and Dugi guides are quite similar to each other, the only major difference being the GUI and a few features. Let’s have a closer look at the GUI differences.
For Alliance it's Lok'Modan, Redridge, Darkshore, Felwood, Stranglethorn (both parts), Plaguelands. Somewhere between 3 - 3.5 of these get you to 60 in like a 16 hours /played, if you queue for dungeons at the same time. I recommend dropping everything at 45 and going to Darkshore-Felwood if you didn't do them yet - they are literally the fastest levelling zones in the game right now, maybe only trumped by Silverpine.
This includes the “Tides of Vengeance” campaign missions, which continue the War campaign introduced when the expansion launched. Two new island expeditions called Jorundall and Havenswood were also added. Weekly quests also require less Azerite than they did in the past, Mythic and player-versus-player islands award more Artifact power, and new vendors were made available.
Blizzard tried something new with Battle for Azeroth, releasing the expansion worldwide at the same exact time around the world. That means that while the street date was technically Aug. 14, the game went live at 3 pm PT on Aug. 13 if you lived on the west coast. This is the first time The Americas have launched an expansion at the same time as the European servers. Players didn't have to watch Twitch streams of people who are in time zones ahead of them while waiting for their own launch times. Everyone could log in and start playing together simultaneously.
As a hero of the mighty Alliance, journey to the seafaring kingdom of Kul Tiras, home of Jaina Proudmoore. Untangle a web of betrayal and dark magic as you encounter power-hungry pirates, witches wielding death magic, mystical sea priests, and more. Explore the stony peaks of Tiragarde Sound, trek across Drustvar’s high plains and red forests, and navigate the intricate inland canals of Stormsong Valley as you convince this fractured kingdom to join your cause.
The idea of the expansion came up after the heroes of Azeroth dealt with so much external threats like the Burning Legion. In their own words, "so when we talk about what's the biggest threat in this world, is it the titan or is it the dwarf paladin that put a hammer in that titan's head"? As such, the enemy (at least during the early parts of the scenario) will be the opposite faction, a "vast army of world-destroying forces".
At the end of Legion, the titan Sargeras was imprisoned, but not before he plunged his sword into the planet Azeroth. This not only devastated a massive area (much of the desert zone of Silithus is now cracked and scorched), but badly wounded the gestating titan inside. While the heroes managed to ablate the worst of the damage (at the cost of the majority of their artifact weapons' mythic power), the world is still wounded and bleeding a substance called "Azerite," which has great magical potential. The Horde Warchief, Sylvanas Windrunner, attempts to consolidate Horde power on Kalimdor and gain a monopoly on Azerite (which is primarily found at the southern end of the continent). Her campaign to do so, the War of Thorns, formed a pre-launch event for the expansion and ends with the major Night Elf holdings on the continent seized or (in the case of their capital city of Darnassus) annihilated. The Alliance makes a retaliatory strike against her home base, the Undercity, which was formerly the human capital of Lordaeron. This succeeds in driving the Horde out, but before leaving Sylvanas saturates the area with disease and toxins that render it uninhabitable. With this tit-for-tat military exchange, the Horde has almost complete control over Kalimdor, while the Alliance has near-total dominion over the Eastern Kingdoms. With further conflict inevitable, Battle for Azeroth takes the two factions to the continents of Kul Tiras and Zandalar to recruit new allies in order to turn the tides of war.
XP Potions: The Elixir of Rapid Mind and Elixir of Ancient Knowledge no longer drop. They can be bought on the AH still but are way to expensive for it to be worth it. The Excess Potion of Accelerated learning is available from your garrison quartermaster but only works for level 91 to 99. As of Patch 8.1 you can also buy the 10% XP Potion Draught of Ten Lands.