Hello Nicole
I think I can help you with the things you are trying to do. Some of it I may have to respond separately just because I need to figure out how I did it again since it has been a couple of years. lol :P
To change the background on your website follow these steps:
1. upload the image you want as your background to your image manager & know the name of the file/image
2. click on the "design" link
3. click on the "template manager" sub link
4. you should then see 3 options to select in the main window (3column.html, box_headers.php and stylesheet.css) select/highlight "stylesheet.css" and the click on the "edit" button to the right
5. I suggest copying and pasting the existing code that is already there into a word file and saving it. that way if you screw something up you can always just change it back to the way it was originally ;)
6. you are going to see a bunch of html codes and stuff. at the top of the coding there should be the words: BODY and stuff written after it (I cannot remember what since mine is already changed) Here is what mine looks like:
BODY {background-image: url("/images/backgroundDD2.jpg"); color: #1a0608; text-align: center;}
7. You will basically need to changes yours to the same code, but after the /images/ you need to type in the name of the file for your background that you uploaded. As you can see my image file name is backgroundDD2.jpg
I am not sure if I changed anything with the color number but you can probably cross reference it with yours.
I hope this makes sense. It is hard to explain this stuff in writing so let me know if you need some clarification.