If you're used it, then it's quite easy. I mean, it's a lot easier with a keyboard and mouse. There is a reason why PC gamers are the best Fortnite players. But if you play regularly with a controller then you won't have any issues. With a bit of practice, you can get used to it especially building quickly. 

I would recommend playing a lot of Team Rumble because the respawn feature can ensure you play a lot and get used to the controls quickly.