There is a variety of cosmetic items for use in Fortnite. These came from various sources, including, but not limited to Battle Pass seasons, a Twitch Prime Membership, buying a Starter Pack, and the Item Shop.
Cosmetic items fall into the following categories: Back Bling, Emoticons, Emotes, Gliders, Loading Screens, Outfits, Harvesting Tools (Pickaxes), Skydiving Trails (Contrails), Sprays, Toys, Umbrellas, and Music. Some outfits are also tied to heroes in Fortnite: Save the World. Cosmetic items are not always available.
From Season 10/X onward, cosmetics are available for Save The World players.
Back Blings
Back Blings are cosmetic items that can be equipped onto the back of your player's character. One of the type of Back Blings that you can use are called 
Pets.
Emoticons
Emoticons (Emojis) are cosmetic items that can be equipped in the use of communication. It can be used for comedic, fun, sad and or even tactical purposes.
Emotes
Emotes are character styles that are used for expressions. Emotes can express show-offs, dances, taunts, and can even require partner co-op.
Gliders
Gliders resemble characteristics of a parachute. Exiting the Party Bus is just one of many instances where you can use your glider. One of the type of gliders you can use are called 
Umbrellas.
Loading Screens
On screens where you have to wait to get in a game, or have recently returned to lobby, players can choose a preference of the loading screens that they'd like to use.
Music
Sitting in the lobby, you can toggle music on/off. If toggled on, you can choose a preference of the music that you'd like to listen to. These can be earned through tiers and or challenges.
Outfits
Outfits are unique styles that can be earned from tiers, challenges and or even bought from the item shop. All skins are based off of other default character models such as Recruit Jonesy and Recruit Ramirez.
Harvesting Tools
Harvesting tools are weapons that can be used to break objects or even fight other players with.
Contrails
While free falling from the sky, a contrail can be used that follows your character. Contrails are mostly seen when exiting the Party Bus.
Sprays
Sprays are a cosmetic way of expressing yourself. You can spray objects such as walls and floors that will leave a spray stain.
Toys
Toys are fun cosmetic objects that can be used for games.
Wraps
Wraps (camos) are used on weapons to change its color and or pattern.
