"Gain XP" is one of the possible Challenges in Fortnite Battle Royale.
For this challenge, you need to gain a specific number of Season XP.
Amount of XP and the reward will differ based on where this challenge appears. (i.e. daily challenge, weekly challenge, etc)
Also certain Battlepass challenges such as the Calamity challenges and the Dire challenges require you to gain XP to unlock more styles for the skins.
Refer to the XP Chart for XP and level requirements.
Lil Kev Challenge
This is also a Lil' Kev Challenge where you have to gain 5,000 XP and you will get another 500 xp as a reward. Doing all 3 of the Lil' Kev Challenges awards you with the rare Lil' Kev Back Bling.
