When you are Level 20, go to High Prefect Osborn (Gludin) to become an Orc Raider. By l2hub
Steps from the game client
Defeat Ratman Leader
Quest that must be fulfilled to change occupation to Orc Raider. Prefect Karukia says that Orc Raiders must prove that their courage and loyalty are without fault. To prove your courage you must destroy the Goblins and their Kuruka Ratmen helpers that are ruining this land. Kill Goblin Tomb Raider Leaders and Kuruka Ratman Leaders.
Prefect Karukia orders you to kill two traitors who betrayed their tribe and went into hiding with Umbar tribe. Take their heads and go to Prefect Kasman of Gludin Village. Read the betrayer's report and by using the information in it, slay the Orc betrayers!