You can install the ubuntu USB creator to make a bootable USB, but I don't think that's the issue. Did you disable secureboot? I think Ubuntu has a secureboot key, so it can install on a Windows 8 system.
If you just want Cinnamon, you can install it in Ubuntu. If you want all the Mint goodies though, I would try disabling secureboot and installing Mint then.
After you verify you can boot into Mint, something else you can try is adding the Mint repositories and installing all of the Mint goodies from there (mint-meta-cinnamon, or mint-meta-mate if you prefer). This might result in a broken system though, so only try this if you were going to reinstall anyway. It might end up being faster than completely reinstalling if it works.
Running on a 4-slot toaster @ 60Hz