Nation: Windurst
Mission: "Lost For Words"
Areas involved: Windurst Woods, Maze of Shakhrami, Inner Horutoto Ruins, Windurst Walls
Jobs of involved NPCs (where applicable): THF, BLM, SMN
Excepting the level 80+ goblins and skeletons now roaming the "Beetle's Burrow" portion of Inner Horutoto Ruins, the highest-level aggressive monsters near the places that need to be reached are Maze Scorpions in the Maze of Shakhrami, which are T/VT to the target level of 20; many duos and most trios at the target level won't find fighting their way through too challenging.
As I noted above, in this specific example it is possible to avoid the aggressive level-80+ monsters. However, with regards to storyline and lore, there is (and should be) absolutely, positively no reason to go anywhere near Jeuno or Selbina before any nation's 2-3. Relatively adequate gear is available for sale at these missions' low levels from NPC shops in starting cities or, at the very least, in exchange for CP.
"Go to the Auction House and..." should never be a requirement for any mission.