My PS4 crashed, I just formatted my PS4 and I do play Fortnite on it, I lost all my games, so I got a hard drive from a friend that plays Fortnite.
Can I get all my data back, so I don’t get to download the whole game again?
It depends on what you mean with "data".
The game will need to be redownloaded, even if you have it on a Friend's PS4 Hard Drive, as the drives only work with the consoles that they were created with. You could try copying the game to an external drive as long as both of the consoles are running the latest version of the system software, but that might not work.
Your game progress is stored in your Epic Games account, so you just need to log in with the same PlayStation account you used before that is linked with your Epic Games account.