The expansion allows players to level up to level 120, an increase from the level cap of 110 in the previous expansion Legion. Initially, there will be ten dungeons included with 8.0 with Mythic Plus versions of the dungeons and the first raid, Uldir, being available soon after the game's release. Following the beginning of preorders and the release of four allied races in January 2018, the number of character slots per server was raised from 12 to 16; with the launch of the expansion in August, it was raised to 18, to make room for the two additional races unlocked with initial content. The number of available bag slots in the player's backpack, which has been fixed at 16 slots since the game's release in 2004, will also receive an increase if an authenticator is attached to an account.
Allied races: Our new allies will join the factions and players will be able to unlock the ability to play their race. There are 6 planned for launch. Horde: Nightborne, Highmountain tauren, Zandalari troll. Alliance: Void elf, Lightforged draenei, Dark Iron dwarf. Additional races are planned for the future. Receive a Heritage Armor set, if you level an allied race character to level 110.
Heirlooms. At the bare minimum you make sure all the armor pieces upgraded to 110, since this is the lion's share of your experience increase. Neck and Ring upgrades are secondary, but still important due to being able to enchant them. Trinkets can't be enchanted, but you'll want them at max as well, if only to save time by not having to worry about replacing them as you level.
Tiragarde Sound and Stormsong Valley are both fairly similar zones, but Stormsong is a little longer, meaning that you might not even have to finish it to hit 120. Tiragarde also comes with a bit of a warning. There are plenty of side quests to do in the zone after you finish the story quests. Don’t do them. It’s not worth the time or the experience you’ll get.