Update!

Hey, I was able to change my background!  Thank you, Sandra, for figuring out what I was doing wrong!  You can see that I uploaded a new drawing to work with.

Hello!

Here is my finished sunflower.  I was never able to change the background color despite restarting with a new file four times.  Each time I got to the part to choose the paintbucket tool and change the background, my cursor would change from an arrow to a "no" symbol!  I could not figure out why!