I defintely think at 118 you should go and do all four of these parts. These are required to unlock World Quests and probably take about 60-90 minutes to get through. If you do these whilst levelling (especially all in one go at 118) then when you hit max level you're ready to go on WQs. You can go finish the zones quests at your leisure over the next weeks/months or never even finish them if you don't care about questing.
Lastly: The zone order I recommend for Horde is Vol’dun- Zuldazar- Nazmir. Vol’dun is definitely the most challenging of the bunch and having the use of your Legion gear and leggos will smooth this zone out. Nazmir is the easiest of the bunch which is nice when things start to get a little grindy past 116. For Alliance, I recommend Drustvar- TS- Stormsong. Same logic as the Horde side, in my opinion Drustvar is the hardest and Stormsong is the easiest for when it gets grindy. I would recommend you waiting to do any of the War Campaign until you are capped because it just takes you out of the way. I also recommend not killing a single rare mob or picking up a single treasure because in my experience it is just not even remotely worth it. The gear scales up on the rare mobs so its smarter to keep them till 120 anyways. After you are done leveling, I do recommend taking the time to do all the quest at the Faction Outpost in your enemy territory. They do provide rep for the Honorbound which helps. Most of them are quite easy. If you do not level in Warmode, you will usually hit 114 from your first zone, 117 from your second, and cap 120 about 2/3 in your final zone.
For scribes who can't and won't go all in with crafting Darkmoon Cards, an attractive alternative is to also dip into the other "odds and ends" inscription items. Particularly popular and profitable are BoE shoulder enchants (both blue and purple rarity), Runescrolls of Fortitude and the pair of companion kites. And if players had to choose only one of these, BoE should enchants are "easily one of the best money makers, in terms of gold per hour" because of their consistent demand and persistently solid wow gold price
As you're leveling, I generally recommend you just follow the natural flow of the progression through each zone. They're laid out fairly reasonably. But don't be afraid to hop around, especially if you're near a quest objective. You shouldn't actually need ALL of the zones listed to reach 62. Pick the ones you like best. It's much more important to simply be as focused as possible and flow from one quest to the next.
With 8.0, Blizzard introduced World of Warcraft’s second ever stat squish — where all the numbers in the game are lowered across the board for clarity. While it may make the game easier to read, it has caused some serious in-game problems. Since the patch, Blizzard has been throwing out hotfixes each day, fixing things that the stat squish either forgot to alter or simply broke.
Congratulations on reaching Level 120! There are a myriad of new things to do. The first thing you should do is head to your faction hub ship where you have been doing your mission table quests and footholds to pick up and complete the quests necessary to unlock World Quests. World Quests will provide you an opportunity to grind reputation levels, acquire gear, and gather Azerite. There are tons of new things to do that we will cover in our Level 120 Battle Guide found here: Level 120 Battle Guide