how do i clean the junk off my 6 year old desktop

By desktop do you mean your computer has more than 85% of the hard drive full?

Or do you mean that the screen in the Finder has too many icons on it before you open any windows?

If you mean the latter, the Desktop folder is available when you go to Finder, File menu -> new window.

Finder menu -> Finder preferences -> Sidebar. Check just the desktop, and click on it in the new window's sidebar. From there you can clean the icons on your wallpaper part of the desktop and move them to another folder you create with File menu -> new folder.

If you mean the hard drive, see my FAQ*:

http://www.macmaps.com/diskfull.html

P.S. PowerMacs can't run Yosemite (10.10.3). The last PowerMac was made 9 years ago. Your signature provides a time conundrum.

You posted to the Classic forum, which has to do with 9 year old or older Macs, and their emulated operating system, or boot operating system on 2003 Macs and earlier. Please properly identify your operating system (go to Apple menu -> About This Mac), and your Mac model:

http://discussions.apple.com/docs/DOC-6413

and repost to the correct forum, if needed:

http://discussions.apple.com/docs/DOC-2463

* Links to my pages may give me compensation.