As I mentioned in my other answer, this is not the correct website for Fortnite questions. I was able to answer your question about pausing downloads because the launcher acts the same way for both UE4 and Fortnite, but transferring Fortnite between 2 PC’s is a different story.
Please ask your question on the Fortnite forums here:
https://www.epicgames.com/fortnite/forums
They will be able to help you further there.
Thanks