Stormheim is the zone you want to start it. For some reason Legion treasures are not worth any experience like they are in WoD...except in Stormheim. I haven't been able to find out any reason for this, and it's possible it may get fixed/nerfed at a later date. But for the time being you REALLY want to jump from treasure to treasure to augment your quest experience.
Instead, go to Timeless Isle and take the portal to Gorgrond. From there, fly to your respective faction starting zone(Frostfire Ridge or SMV), go to your garrison, and do the quests to unlock your garrison(A short quest chain beginning down near the water where you'd otherwise start after the Dark Portal scenario). For now DO NOT collect any more treasures than absolutely needed to buy 2 experience potions! Treasures continue to be worth superior exp/h all the way to level 104!!! You don't want to begin collecting them until lvl 100 or later.
I made some route changes to the Horde levels 43-44 sections. I have swapped 44 Dustwallow Marsh with 44 Desolace (the entire sections). This allowed me to do Deadmire (at lvl 43 instead of 38) and then go stop at TB to turn in Deadmire + The Black Shield at the same time, then fly quickly to do the Desolace stuff. Doing 44 Desolace is now mandatory because I think its faster with the new routes. This will also make the level 53 grind much shorter. I think these were great changes.
Eventually, the Alliance finishes its preparations and launches an attack on the Zadalari capital of Dazar'zalor, their goal being to sever the budding alliance between the Zandalari and the Horde by dismantling the Golden Fleet and capturing King Rastakhan. Despite Anduin and Jaina's desire to capture him alive, Rastakhan is overwhelmed by the power of his pact with the Loa Bwonsamdi, and the Alliance champions are forced to slay him. Enraged by Rastakhan's death, Horde champions launch a vicious counterattack on the withdrawing Alliance forces, which ends with both Jaina and High Tinkerer Mettatorque gravely wounded. As the Alliance leadership debates their next move, Sylvanas, infuriated by the Horde's defeat, resurrects Jaina's long dead brother Derek Proudmoore as a Forsaken, an act that horrifies the surviving Horde leaders, with the intent to use him as a sleeper agent to destroy the Proudmoore family from within.
Dugi and Zygor both had their guides updated before Mist of Pandaria was released and both guides are kept updated with all the patches and changes to the game. Dugi is way faster with updates and has a lot more. Zygor seems to hold out and then do a big update. With new content such as guides etc, Dugi is definitely leading the way with Zygor usually many months behind. Zygor now offers the same number of guides as Dugi but it took them a long time to catch up.
You can try joining a Discord server themed around the class you’re playing, how you like to play World of Warcraft (achievement hunting, dungeon-running, player-versus-player combat, etc.), or your location, to name a few examples. World of Warcraft also has player communities built directly into the game. Find a community themed for newbies, or whatever else you want, and you’ll have a great resource to go to with questions. You might even make a few friends (or fellow adventurers).
-Gameplay- Gameplay has largely been stripped down to be a shell of its former self. This trimming has been going on for several expansions, but now it's even worse. Classes only have so many buttons which has resulted in very little skill involved in PvE (even PvP is a faceroll for most melee, lacking any sort of depth and decision-making as it's pretty clear what buttons to press in any given situation) and it's become more of a gear check. This expansion gave zero new abilities to classes, only took them away.
Some quests in my guide are marked as "SKIP" and colored in red. These quests are simply either too hard to solo or not worth the XP/time and are skipped. My guide will only list SKIPPED quests if the quest is a direct follow up after completing a quest, not one that you have to click the NPC again to get it. If you hover over the skipped quests, it will give info on why it is skipped in the guide (unless that info is already listed directly in the guide text).
If you want to spend as little time on your alt as possible - just do Legion Invasions. You can use sites like (https://wow.gameinfo.io/invasions) to track when the next invasion will be. Log in, fly to the closest world quest, and once there - right-click on the quest's name in your quest log and "Find Group". Sign up for some group, or if there's none - just start your own immediately, and people will come to you. It is 10 times faster to do invasion quests in a group. Once that particular quest is complete - leave the group, and fly to the next one, where you should find another group. Don't expect the group from one world quest to follow you to the next. Then you simply log out until next invasion. You can do 1-2 invasions a day, and each invasion will give you about a level or 1.5 of experience, if you have full heirloom gear. Each invasion will take about 20 minutes.