System files/folders are hidden by default, even from admins. And personal folders have limited access methods by default. So those are two reasons files/folders might be hard to find.
The downloads folder should be at C:\users\Derekfoxes\downloads.
To turn off the first item I mentioned you can go to Windows Explorer ... Organize > Folder and search options ... view tab ... uncheck "hide protected operating system files". Then close and reopen windows explorer. Note: with these files visible you will see some odd things such as desktop.ini files showing up in many folders including on the desktop.
To resolve the second issue where you can't even access your own folders. This is a permissions issue and I find the easiest way to resolve it is to install the
Take Ownership script and then in Windows Explorer simply right-click and choose Take Ownership of folders for which the system is limiting access.