"Documents & Settings" is an old name for the Users folder in Windows.
If you run Command Prompt (aka "cmd.exe") using the normal shortcut in All Programs>Accessories, then that will start in your user folder. Normally, that's something like "C:\Users\Ida", if "Ida" happened to be your login name.
In that folder are subfolders with different contents. The ones you will be interested in are pretty self-descriptive: Desktop, Documents, Downloads, Music, Pictures, Videos.
Several other folders are there, too. If you didn't create them, leave them alone. They are managed by the system or by some application you've installed.
I suggest that you put any files you create in a subfolder of Documents or Desktop. (...but media files go in Music, Pictures, or Videos, of course.)
Desktop folders are a great place to put things you'll be working on with CMD. That creates an icon on the desktop that you can Shift+Right-click on and choose "Open command window here" to get to work right away. (Try it!)
Shared items are stored under the "Public" user's folder, usually something like "C:\Users\Public" and that will have subfolders for Documents, Downloads, Music, Pictures and Video that are visible from any login on your computer.
That should help you find your way around your directory structure. For a pictorial view, you can always open the file explorer, which has your username as a top level directory (along with Computer, Network, Recycle Bin and others), and that will display your C:\Users\[name] folder.