So my laptop was working fine earlier today. I closed it and put it in my bag and drove to school. It fell out of my bag in the car while I was driving, but was like a max 1 foot fall. When I turned it back on it said Reboot and select proper boot device. I checked the boot order and it was all correct. I tried spamming 0 and that didn't work. What can I do? I don't have a CD drive to reinstall windows 8.
I'd suggest that you try the HDD with another computer. If it's recognized, backup your important data and download the HDD manufacturer's diagnostic tool (or a 3rd party one if the manufacturer doesn't offer such a tool) and test the drive, to see what's the situation with it.
As for the Windows 8 installation, you could always create a bootable USB flash drive and install Windows this way. About the Window 8 registration, I assume yours is OEM (your laptop came with Windows 8), so you'll have to get the exact same version and you should be able to register it with the key you have for your laptop. Although it's better to get in touch with MS support just in case, before you try that.
But still, I'd recommend that you try the drive with another computer and backup your data before trying to reinstall Windows.