Episode 1

Yeah, the requirement for the first quest in the chain is the last Basic training your Job Instructor gave you long ago.
[job]'s last training session, I believe.

 Spoiler

Warrior's last training session (FFFFFFFUUUUUUUuuuuuuu---)
-> Meeting the Training Instructor
-> Advanced Training-1
-> Advanced Training-2
-> Reporting the Training Results
-> Meeting Ervine
-> Inspecting the Water Pipe
-> Sticky Slimes!
-> Visiting Henesys
-> What Does Chief Stan Like?
-> The Reason Why Chief Stan is Livid
-> Searching for Clues
-> Heading Over to The Nautilus!
-> Investigation in Progress
-> A Special Wine
-> Solving the Mystery
-> Catching the Suspect
-> Who Changed Him?
-> Dances with Andras!

=> Who Broke the Seal of Andras/Crocell/Marbas/Valefor/Amdusias? (4 quests, available to all)
=> Revealed Identity (available to all)
=> The Rememberer's Training-1/2/3 (3 quests, requires lvl 25 to initiate)
=> Secret of Astaroth
=> How to Avoid the Stink
=> For the peace of Victoria Island...

Brb pasting the quest chain.

So, if you finished the training sessions as a young Mapler, you only need to be 25 or higher? Or am I missing another below x level requirement/ reading you wrong?