I think that the most engaging way (not the most efficient in terms of time spent) to learn stuff as a very new player is by "tutorial campaign". Unlike the vanilla campaign (which really doesnt teach much, it just restricts units/buildings) it would be much more focused and showcase specific mechanics, encounters with specifically restricted toolkit.
- Start with the player only controlling the com and having to escape from an invasion, pretty much a on rails mission, teach about ACU health, survivability and overcharge specifically.
- Teach player how to evade an incoming air snipe, let them run to allied mobile AA safety (teach about T2 gunships vs com health vs AA relationships), dont let them control units yet.
- At some point force the players to have certain upgrades and teach the difference between a no-upgrade sera com and a double nano double gun monster for example.
- Have a situation where player is required to collect X reclaim in Y amount of time so that they can overflow enough mass to let allied AI finish a needed experimental, otherwise player looses. Reward is of course cool experimental saving the day in the nick of time.
- Put the player in a sitation where he can clearly see how having radar affects effective shooting range.
- Have a situation where a player needs to surround kill an enemy com with a fixed number of T1 spam that he cannot increase and one where he has to fend of T1 with com (the beginning of prothyon is quite nice in this regard, but i don't like the second half)
- Have situations where the player needs to counter higher tech units with cheese / lower tech units, and the other way around where they micro a small number of higher tech units against lower tech ones.
- Basically make it fun and interesting first (good story is important for that) but weave in lots of situations that all teach one specific thing.
Some things cannot be thought well like that, for example general tradeoff between eco / tech / bp / units and general game progression, but make sure that the player is aware of the entire toolbox that the game gives them. Its much less frustrating to get beaten in PVP if you at least have some idea about all the tools.
Problem with this is that of course if big balance changes happen, that might cause certain situations to play out differently than planned. The idea itself is not new, i think several people have mentioned the small starcraft missions that you play with fixed units, but those seemed a bit boring because its just the same thing over and over with different units (and im not suggesting to always put the player in fixed unit situations, that is too repetitive).
At the end of the day, if learning is not enjoyable, not many people are gonna try to get gud. When you first joined FAF, your goal was probably not to dominate ladder rating. The competitive aspects comes after you have seen the potential of all the tools that the game provides. The game must prove that its going to be worth the time spent to improve.