https://www.gamespot.com/articles/get-free-fortnite-battle-pass-tier-by-doing-secret/1100-6460784/

We're a few weeks deep into Season 5 of Fortnite, and Epic continues to roll out more challenges for players to complete. If you manage to finish all of the challenges in a given week, you will also complete a corresponding Road Trip challenge--Season 5's version of Blockbuster challenges. The reward for completing a Road Trip challenge is a special loading screen, which contains a subtle hint directing you to a free Battle Pass tier somewhere around the island.

If you complete two weeks' sets of challenges, you'll unlock the second of Season 5's special loading screens. This one features a group of characters driving golf carts around Lazy Links, the new golf course area that replaced Anarchy Acres in Season 5. You can take a look at the loading screen below.