Open a finder window
Look in Documents => Parallels
You should see a .PVM file in there for the Windows 8 VM you created.
If you delete that then when you start up Parallels it should prompt to say it can't find the VM, if it doesn't show you a list of VM's then right click on the Parallels icon in the dock and choose "Virtual Machines List".
The only way to install Windows 8 for personal use in Parallels is to buy the System Builder edition, or install a previous version of Windows you legally own and upgrade using the upgrade license you bought.
If it's for development work and you have an MSDN subscription or similar you may have it from there.
Easiest way for home use is to already own an existing version of Windows, once you activate Windows 8 you can't simultaneously have your old version of Windows installed on the same or any other machine.
Try and solve your issue of removing the VM first, and then see if you have any questions on Windows 8 licensing.
Are you sure you aren't legally entitled to use the upgrade version you bought? Do you already own a retail version of Windows XP, Vista, or 7 for example?
There are ways to install straight to Windows 8 as long as you own the older version of Windows (Without first installing it and doing an update) - It should be fine follow that specific method as it was talked about on Microsofts Channel 9 at one point.
