are you able to start cmd.exe or powershell as an administrator? (elevated)
the net.exe commands can run as not elevated and give you your name and the administrators name just in case you have different logon names with different rights.
you can also use a user interface but I have been using this OS since before it had a UI and I tend to use the cmd line apps.
maybe something like
how to change folder and file permissions in windows 10 - Microsoft Community
bring up file explorer, right mouse click on the directory you want to check the rights to, select properties then secruity
you should be able to see who has rights to the directory . my documents folder has rights to
SYSTEM
my microsoft email account
and
administrators that are defined on my local machine. (shows as my machinename\administrators)
if i select a user then select the advance button i can change things like ownership
you can also use the take ownership tool( takeown.exe) but people tend to mess it up and take ownership from SYSTEM which is windows.
the end up reinstalling .
best to find out who has rights to the directory and logon with that account or any local admin account and then setting the rights correctly for your non admin
account.
here is a example of how to grant permissions to a directory with iacl
How to grant permission to users for a directory using command line in Windows? - Stack Overflow
C:\>icacls.exe "D:\test" /grant John
🙁OI)(CI)F /T
note that the directory name is in quotes "d:\test"
see the note about the /t option as being require or you will get an access denied error. the note is in the user comments