Batallia Downs -> Jugner Forest -> La Theine Plateau -> Ronfaure. I actually think it's the safest way because Batallia is open wide and it has more space to run around aggro monsters, and Jugner is somewhat the same, but you don't run into many aggro monsters on the path.
You should be fine. Jeuno's map has a map of all four areas of Jeuno, as well as the three right outside Jeuno (Batallia, Rolanberry, and Sauromogue). And Sandy's map should have Jugner on it.
I suggest you leave from Upper Jeuno. It zones to Batallia downs.