adding background to iPod nano

You can only do it by hacking or replacing the firmware on your Nano. Since this is not officially supported by Apple, we cannot discuss this in Apple Discussions.

Search on Google and you'll probably find the info you are looking for.
Just know that if your iPod breaks as a result of doing this, your warranty will be voided.

I just got my ipod nano and the background for the music playback is a flower, is there a way to change it, even to a plain background?

The iPod does not support backgrounds.
If yours is a flower... then you may have a counterfeit iPod.
Did you buy your iPod directly from Apple?

No I didnt, my mom bought it from someone on the internet who sells them, it was bran new in the box though...

Sounds like a counterfeit iPod. It's probably a fake.
Does your iPod look EXACTLY like one of these? (Look closely at the markings on the click wheel.)

1st Gen Nano
http://docs.info.apple.com/article.html?artnum=61688#ipodnano

2nd Gen Nano
http://docs.info.apple.com/article.html?artnum=61688#ipodnano2

No it doesnt. 😟
do you think there is anything I can do about it though?

Sorry to hear about that.
Unfortunately, I don't know what you can do about it.
You might see if the person who bought it can report the fraud to Apple, with all of the details about where it was purchased from.

Try to get a refund thru the purchaser. If it was purchased with a credit card, have your Mom notify the credit card company immediately.