Learn how to use the OS X Mountain Lion Finder feature to improve your knowledge of the Apple operating system.
If you want to remove some of the clutter from your computer, you can delete files and folders you don't need. This will move them to the Trash (which is just like the Recycle Bin in Windows). Then, if you're sure you want to permanently delete them, you can empty the Trash.
On some Macs, right-clicking may be disabled by default. If you're unable to right-click, you can just click and hold the Trash icon until you see the Empty Trash option.