From your open company file:
Select the File menu at the top, select Open or Restore Company.
Select Open a company file radio button, then select Next.
From the Open a company window, select Cancel.
On the “No Company Open” window, select “Open a Sample File” from the drop-down arrow.
Create a portable copy using the sample company file and save it on your Desktop.
You can take a test-drive from a sample company file.
To switch back to your own company file again:
From the File menu, select Open Previous Company menu, then select your company file.
This is how you go and back forth to learn QuickBooks Desktop on your own without never messing up your own books.