Summarize this article:

You'll need to use the "Terminal" app to hide your folder.    This is in the top right corner of your screen. You can also hold ⌘ Command and tap Spacebar.     Your folder should now be hidden from view! Hidden folders on a Mac are invisible unless you type a specific command into Terminal.

Summary:
Two-finger click your desktop. Click New Folder. Type in a name for your folder. Tap ⏎ Return. Click the magnifying glass icon. Type in "Terminal". Tap ⏎ Return. Type chflags hidden. Drag your folder into Terminal. Tap ↵ Enter.