Hello Milena,
Based on your screen, it looks like these files are on a Windows system. Your first step will be to set up a shared folder so that your Qiime VM can access these files.
There is a great tutorial on how to do this here: VirtualBox Shared Folders - #2 by thermokarst The instruction as the end are a little different for MacOS and Windows, but the start is exactly the same.
Let me know if you have any problems setting up the Shared Folder on the Qiime VM.
Colin