https://www.gamespot.com/articles/fortnite-guide-search-letter-locations-tomato-town/1100-6458641/

Season 4 of Fortnite is officially underway, and with it, we've gotten a brand new Battle Pass. This works largely like they have in the past, offering weekly challenges for players to complete in order to unlock new skins and rewards. Week 1 challenges are the usual mixture of easy and tricky objectives; here are the key locations and how to complete them all. [Update: All Season 4 challenges are now available. With Season 5 starting on July 12, you only have a little time left to complete them all.]

Week 1's other challenges are much more straightforward and generally rely on a mixture of luck and being in the right location. You'll need to deal damage to opponents using sniper rifles, which is just a matter of finding such a gun and having good aim. You'll want to head to Haunted Hills and search for chests; hopefully, in the process, you'll also get your hands on a Port-a-Fort. If you do, be sure to use it before dying to complete another challenge.