I took the Zygor Leveling Guide for a test-run on my alt account with a level 33 Warlock and a level 40 Paladin. The first thing I noticed was that the quests are selected for your class. I didn’t have to weed out any that would be too hard for the warlock to solo. The other nice thing is that you can skip forward on the quests. Zygor has this option that lets it analyze your level and it gets rid of the quests that aren’t worth doing and shows you only the ones that’ll actually help you level up. It was easy to get my Warlock another 30 levels in only a day of following Zygor guides. The Paladin guide was even easier for me and I never had to do anything but let the guide show me where to go next.
EXPLORE TWO FABLED KINGDOMS – As a champion of the Horde, travel to Zandalar to persuade the trolls to lend their naval might to the war effort. As a defender of the Alliance, sail to the seafaring kingdom of Kul Tiras, home of Jaina Proudmoore, and rally its inhabitants to fight for your cause. Once you’ve successfully recruited one of these proud kingdoms to your faction, infiltrate the enemy’s newly claimed territory.
As late as possible. Early on, you’ll want to follow the missions in Battle for Azeroth right up until you get the option to send a follower on a two-hour long quest. As soon as you get there, stop doing the War Campaign missions. You can come back to them once you have reached something like 119 and a half and finish leveling with those if you want. If you don’t use these missions to cap off your leveling journey, then they’re the first thing you’ll want to do once you reach max level.
The biggest gold maker in BfA for inscription is the Darkmoon Decks. In fact they are pretty much the only truly profitable recipe this expansion. Milling is a pain as you generate thousands of useless ultramarine pigments. You can use some of you crimson and ultramarine inks to craft Tome of the Quiet Mind to get rid of them. I have also found that the item level 300/310 off-hands that inscription can craft sell quite well.
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.