At the present time, there are only four different classes of characters found in Fortnite, including Ninjas, Constructors, Soliders, and Outlanders. Ninjas are incredibly mobile characters that are melee combat oriented, Constructors are great buildings specialists, Soliders are awesome at ranged combat, and Outlanders experts at both scavenging and scouting.
On top of each falling into a specific class, each character on your Team will also have a certain rarity to them (Uncommon, Rare, Epic, Legendary, Mythical). Characters will gain experience through all of their actions, which you can then apply to improve their given abilities. Though only four classes of characters are found within the game at this time, additional classes have said to already be in the long term plan of the game.