It would appear that Marvel and Fortnite are not finished their crossovers yet, as Spider-Man is coming to Chapter 3 Season 1. The skin will be part of the Battle Pass, and players will be able to unlock it by completing challenges and earning XP over the course of the season.
Players will be able to earn Battle Stars that they can use to rank up their Battle Pass, and when they rank it up enough, they will be able to unlock the Spider-Man skin and accessories. Spider-Man appears on Page 9 of the Battle Pass, and is basically the last skin that players will be able to unlock with, although there is a Symbiote suit style for the skin on Page 10.
How to get Battle Stars
Cosmetics are no longer tied to reaching specific season levels. Instead, you’ll earn Battle Stars when you level up and can exchange them to claim Battle Pass rewards in the order you decide. Each time you level up you will earn five Battle Stars that can be spent on a new unlock from the Battle Pass or saved toward a more expensive item.
As you earn season levels and claim rewards, more pages of the Battle Pass will unlock, offering new reward options to choose from. So, you cannot grab the rewards from the very end of the Battle Pass straight away, you will still need to spend some Battle Stars to get those rewards and pages to open up in the first place. Each page of the Battle Pass also has a special locked reward that is only available once all other rewards on that page have been claimed