This chapter of the guide to Dragon Ball Z: Kakarot has a walkthrough for Chiaotzu the Champ side quest.
Time frame: From Majin Buu Reborn - Episode 1: Good News to Episode 2: Time for the Tournament!
Reward: 215,027 EXP, 10x D Medal, Golden Compass
Where to start: East Ravine Area, as Gohan.
To start this mission, you need to go to Olive Village. Chiaotzu is waiting for you there - he will give you an additional story.
Your goal is to collect 10 units of deer meat. You have to go to the specified area and hunt a couple of animals. Then go back to your friend to complete the task.