One thing that was quite daunting in PSO2's beta was just how much content they give you access to almost immediately, and how easy all of that content seemed to be. In PSO and PSP, each difficulty jump was pretty significant, whereas in PSO2 they seem fairly negligible provided you're either a couple levels away from the Hard Mode recommended lvl or have a party of friends to tackle it with. The ease of all the content makes it really hard to decipher what you're meant to be doing and what your limit is, as when all content is clearable it means every activity is always on the table.
So then the main issue with the content not having a clear path or flow then stems from the shear amount the game gives you with little to no direction on what to do first or what to aim for.
Again, PSO was simple in that you beat one area then moved onto the rest, and once you had beaten all areas the next difficulty was a natural step forward. The side quests and content were just extra things to do on top of the main story. It was a simple structure that definitely suffered from a lack of things to do once you reach that 50th or 100th hour of playtime, but it was engaging and easy to understand. PSU/PSP also had a similarly straightforward and easy to understand structure, too, albiet with a bit more meat and complexity.
I know part of PSO2's issue is just almost a decade of feature/content/power creep all combining to create an overwhelming experience, but there really is no path for new players to kind of figure things out efficiently. When my friends asked me what they should be doing all I could really say was "Complete the story up until Alfin starts giving you tutorial missions, and then complete those while just playing whatever."
So yeah, the basic question is simply "What do you recommend new players do while they become acclimated to the game and its insane amount of systems?"