Ahhhh. AppData is a hidden folder. You ll have to make em visible in Windows folder settings or just type \AppData and press Enter behind daddys laptop at the address bar of windows explorer to gain access to the secret AppData place of MS Windows 😉
From this point on I am not able to help, 'cause I only have Spotify Unlimited and am not allowed to download someting.
I assume you wouldn't find it. These files there are encrypted so only Spotify can read them to prevent piracy. If Spotify couldn't proof to the music labels that they are able to protect their music against piracy, they wouldn't give the permission to stream the music.