Well, it all depends on your download speed actually, and it also depends if you are using x86, or x64. For the x86 version (32 bits), it's around 2.5 GB disk space, and it will take roughly around 10 GB on your Hard disk. X64 (64 bits) version is around 3.5 on disk, and takes around 11 GB on your Hard Disk.
So, depending on my download speed (which is only around 200 KB/s, 250 KB/s max), I'd say it would take me around 4 hours and 10 minutes at near max download speed. It depends on where you live, and how much bandwidth can you ISP provide to you. PS: Honestly, Windows 10 is really not that worth it.
So far, the best Windows I've seen is Windows 7 64-bit. Windows 8.1 if you want to use it for work. Windows 10 has some nice features, specially making it compact and all, but it's really not worth it.
But, that's just my opinion.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.