I just leveled this char in about 2 days played time with a few hours of it being afk in cities.What I did was run every single dungeon one time and do quests while waiting in queue.That way you don't get bored and the experience gain is great.Works particularly good between 60 and 90. WoD is a piece of cake if you just have flying and Legion is questing + doing the per zone dungeon for the 100k xp quest.
Before you can write any sort of code, you'll want to have a tool that lets you edit your AddOn files. However do not get overly distracted with the tools themselves while trying to get your first AddOn created. Any text editor, like Windows Notepad can edit the files. All AddOn files are plain text files. The editors can make the coding and many repetitive tasks easier for day to day editing, but it's often very difficult to learn the tools and try to learn the AddOn at the same time.
I've used WoW-Pro for years and in WoD, Legion and now BfA it's been awesome for just going on auto-pilot and working your way through a zone. It has 3 levels of depth you can set, so you can set it to just do 1) the main story, main points of interest and rare mobs and treasure that aren't far off the beaten path; 2) every quest with a more thorough dive into the side stuff; 3) absolutely everything.
We have no idea what implications this might have and whether or not it even indicates anything, since Patch 8.2 is still in testing and a Tuesday launch is more than unlikely due to Essence tuning and Azshara's Eternal Palace, which is supposedly coming shortly after launch. Blizzard said they wouldn't be delaying the new raid like they did with Battle of Dazar'alor.