Read the Arrow's message at a Guardian's outpost
As you may have guessed, you will have to go to one of the six guardian outposts, which we find on the island. We advise you to land there directly and equip yourself, as soon as possible, with a weapon, since the enemies will probably be numerous, without forgetting the guardian of the outpost, who is quite strong.On site, you will have to go to the top of the tower, on which you will find a beacon (see header image) which is simply the message to read. Just interact with it to validate the challenge and be able to move on to the next step. If you have the possibility, land directly on the platform at the top of the tower, you will save time and limit the possibilities of getting killed.
You can also go there later in the game, but there is no guarantee that one of the towers is still in the safe zone.
Below are all six Guardian Outpost locations in Fortnite, in case you don't know where we find them.