I know GFX is the choice of most but i cant find where to download and use it at? if you can help thanks

First off, Gfx is the abbreviation for Graphics, and there are various programs to use. Photoshop tends to be the all-time favorite, but it's so expensive, people use other alternatives. And the most popular alternative is GIMP, which can be downloaded free here: http://www.gimp.org/downloads .

GIMP is a very capable program as said above. However, if you're just starting out you might want something like Paint.NET. Personally I consider it as an 'upgrade' to the default Microsoft Paint, even though it isn't of course. It provides just enough features to be worth installing, yet doesn't swamp you with them and confuse you. It's the ideal stepping stone to progress to GIMP or Photoshop (if you're willing to pay).

This is all assuming you are using Windows of course, and that you were actually looking for image editing programs. Your initial question was very vague.