Walk-through:
1) Lieutenant Anderson is located roaming next to the gate in Edgeville, leading to the Wilderness. He asks if you're intested
2) Based on your class, you may have multiple options (i.e. multi-classed).
- Fighters will have the option to join the Varrock militia, or Falador militia. Both are pretty much the same, it's just personal preference (i.e. if you like Falador more)
- Rangers will have the option to join the Lumbridge militia, which is a a group of rangers from the Rangers guild in Kandarin, hired by Duke Horacio.
- Wizards will have the option to join the Tower wizards at the Wizards tower.
- Rogues will have the option to join the Phoenix gang, which are offering support for the Wilderness wall defences in Edgeville.
3) Depending on your class, join the appropriate above by talking to the leader of each one.
- Varrock militia HQ is located west of Varrock Castle
- Falador militia HQ is located in the Falador farmlands, close to the stream.
- Lumbridge militia is located in a camp just north of Lumbridge castle
- Wizards tower is south of Draynor, talk to the head tower wizard.
- Phoenix guild is located south-east of Varrock, marked as V.T.A.M (Talk to Straven down the ladder in the small house).
Note; Players with multiple classes can choose 1 of 2 choices for example, a level 1 wizard and level 1 fighter can join the Varrock/Falador militia, or the Tower wizards.
4) Once spoken to the appropriate leader, you will join as a reserve, handed an upgraded version of level 1 gear and combat xp.
Quest Complete!