Unfortunately, the 'system' put in place to teach people basic things in Final Fantasy 14 is 'suppose' to be the novice network and mentors.
This being mentioned, most know this system is not good.
There is nothing in the requirements of being said mentor that would indicate someone actually knows how to play the game. The people I have come in contact with were all similar, at the least on my data center, with the exception of some actually good mentors. This system is just not good. I know people wish to speak with one another, and there is a huge social aspect to this entire thing. On the surface it was a good idea, but not everyone learns the same way, some do not care to learn, and on the other end of the coin the people teaching do not know how to teach, or do not actually know anything and are now going on to com beg in their bikini's so they can get their "oooo wooo totes kawaii mount pwease"
At the very start of my journey into FF14, I wished for advice, some help, and wished to learn things. I would say "I was new", "This is my first time here", "I am new to so and so class" or "I am new to tanking in this game, be gentle". Now the advice always given was "Aoe", "Use your super easy to learn (at least to me) three button rotation", "I'm a healer main you can not cleanse 'sludge'", or even "you can not use certain skills you can use on Trial bosses". I began to learn early on that the 'mentors', 'healer mains', 'tank mains', and people with multiple level 80 classes leveled were not going to help me learn anything.
I understand now that a crown and all of your classes leveled means nothing at all, and I was naive to even think someone with those things could actually teach, or would actually give good advice.
I am new to THIS game, I am not a brain dead idiot, at least I do not believe I am, but I am also not pompus and think I could never be wrong about things, even about being a brain dead idiot. Maybe I truly am, I am secretly in a coma, and this is my purgatory as punishment for being some dictator of futures past.
Coming at this thread from the perspective of someone wishing to learn appose to someone who is staunchly appose to learning and wishes to 'play their way' in a perfect synchronicity with the burger king crowns, ironically.
I am unsure what you feasibly could do for those who wish to play farmville, and watch netflix while they are waiting for their memories within Syrcus Tower for the seventh week in a row placing their cryplurker gear on at the start of the duty. I would like people who are actually willing to play this game to be able to play with others who also wish to play this game other than party finder, discords, clicky fc's who trick you into joining so you can boost their fc levels/points via 'teaching' you how to craft for actions people will never activate.
For those who wish to learn, having content from ARR fixed or tweaked to be similar to some of the newer content would be a good start. If I had an amazing fight like I had within the introduction to Bozja at the beginning I would have learned even faster how things were going to be in the future. A trust system that isn't super buggy like the squads in the grand company would be nice. I am use to older games, so all of these things helped me, but I could really understand these things just kind of not helping at all.
The actual class quests not being so weird, like the scholar quest you have to keep clicking to npcs and cleansing them so you do not fail the duty. Maybe put those people in your party. All the way at the start don't tell me to just dps as the healer let me do both and have the system not be clunky. Fix the older prompts that still say to 'Tank with your Carbuncle' and 'Tank with Titan-egi' would be a small minor change. I know they most likely will not fix any of these things, but I do know for a fact I did not learn how to tank via my numerous times going out to fight Opo-opos.
The way I have been learning honestly is just going into content, and testing things out with my partner. Nothing teaches you better than to go through all of the phases of every boss without it dying in two seconds because you have a full party. Trying things out with minimum ilvl and actually having the time to learn things maybe die a few times and learn from mistakes that happen. I was honestly devastated when I got to Shadowbringer, and I couldn't go through and practice with my partner, but could only go through via the 'single player co op experience'.
Sorry for the long post. TL;DR: Maybe fix some of the older job quests so they are up to date, allow for some system to test mentors instead of it being commend based, and make the gear bigger in the duty list so people know unsyncing is a thing and you can go in to dungeons and practice with someone. Oh! and maybe scale the mobs in those dungeons if you are solo and have no friends that is not just 'the squad'. By scale I mean allow for the dungeon to be challenging but not unfair, not 'scale' and make everything a one shot.
Also, I know a ton of people will lose their minds about this, but I kind of wish to know what killed me. The only time I can find this out is going through numerous logs. I know having a outside tool makes people weird, but at least give us the basic info, the battle logs are horrible.