For this challenge, you'll first need to acquire Bars, the currency used to recruit the many NPCs in Fortnite.
You'll get these bars from chests and the rare Loot Llamas, but also by looking in cash registers. You may even find some by smashing a sofa! You'll also acquire Bars when you take down opponents.
After getting your hands on 100 Bars, head to an NPC to recruit them. The locations of some are found below.
Once hired, an NPC will follow you around, defending you against your enemies.
As a special bonus, you'll be rewarded with double the usual XP for this challenge.