If you are looking to access your Linux files from Windows, this guide should hopefully be helpful to you.
This location will likely change depending on the version and when you set up your WSSL. At the time of writing this (May 2020), my files for Ubuntu 20.04 are located at:
C:\Users\%username%\AppData\Local\Packages\LINUX_DISTRO_NAME\LocalState\rootfs
For example
C:\Users\%username%\AppData\Local\Packages\CanonicalGroupLimited.Ubuntu20.04onWindows_79rhkp1fndgsc\LocalState\rootfs
Older locations include:
C:\Users\%username%\AppData\Local\Lxss
- For WSSL 2:
\\wsl$