You can work wonders with CC3, but there are things you can do with Photoshop, GIMP or PSP that you can't do any other way.
My suggestion to anyone who is starting out on this forum is to try a variety of tools and not limit yourself to just what you can do with the tools you already know or have. There are free tools in pretty-much every category.
Good luck, welcome to the guild, and please don't wait until you're finished to post your work. The journey is almost always as much fun as arriving at the destination.