1. Buy the scroll from the NPC that gives you the quest.
2. Keep running 3-1 until you get 2 drops from the giant Scorpion.
3. Just keep on running 3-4 (which used to be 3-5) until you complete the next three quests.
Technically, you can do 3-1, 3-2, and 3-3 as well, as the 3rd and 4th quest drops are from the lizard people (5th is drop from 3-4's boss), but if it's anything like it was on TW Elsword, everyone's going to be running 3-4.