Most heirlooms only work in a limited level range in their default form and must be upgraded to work at higher levels. That costs gold, and you’ll need around 30,000 gold to outfit yourself with a fully upgraded set (counting only those that give you bonus experience). You may need to spend some time on a boosted character to acquire the gold you need to outfit another character with heirlooms, but it’s well worth the effort.
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.
Patch 8.1 added paragon reputation awards, similar to what was offered in Legion, except these caches will not contain mounts as rewards. Earning the paragon caches requires acquiring 10,000 reputation after hitting exalted. The rewards are 2,500 Azerite, 4,000+ gold, 20 Service Medals, and 500 War Resources as well as the following toys and recipes:
Congratulations on reaching Level 120! Now that you have hit Level 120 we recommend looking at our Easy mode page and Talents section to learn how to play at max level. To get yourself prepared for the end-game content ahead, we strongly recommend this Battle for Azeroth Raiding Lexicon/Spreadsheet by Medivh. It is a gold trove of information that will help you when gearing up in Battle for Azeroth and more.
The Horde will now control most of Kalimdor, and the Alliance most of the Eastern Kingdoms. For a low-level character the quests and storylines won't change, but for high-level players many zones will see changes via phasing. Teldrassil is burned and Undercity is in ruins as the story progresses by phasing. At max level Arathi Highlands and Darkshore are phased to be updated to reflect their status as locations for Warfronts.
DoTs: Assuming that the mob is going to live for certain periods of time, it is worth it to place DoTs up. If the mob lives for at least five seconds, cast Pain. If it lives at least seven seconds, cast VT. The ideal time to cast DoTs is when it would be replacing Flay, but you can substitute Blast if the mob will live longer. Make sure to cast Bolt on cd though!