So, Arch Linux is one of the toughest for a new user... are you sure you want to go with that? I'm not familiar with it myself but others here are and maybe they can give better info. You might prefer Slackware, for example, as it claims to be the most Unix-like of all the Linux distributions, and it is the oldest distro also. All Linux distros have a Unix-like command prompt (often BASH, but not always), so you should find your comfort zone again soon.
But, on a general note, I would question putting a "torrent" on a USB stick. Do you mean an ISO file? You say you're using Arch, but your post title refers to installing from Win 8. I'm really not clear on what your exact problem is, or what it is that you are trying to do. If you are trying to install Linux on a Windows 8 computer, you will probably have to learn a bit about UEFI (the firmware that has replaced BIOS).
If you haven't made Windows 8 "recovery DVD's" yet.... now would be a good time. Also back up anything on your Windows drive that is important to you. Because of UEFI, it is easier than ever to stumble and hose up the computer to the point that you will need to start over again from scratch. If you don't need or want Windows any more, it will be much easier to install Linux and use the entire hard disk.
Good luck!