wordpress theme looks waful

please any advice also this is my firat wordpress blog so i am a newbie so please explain in simple terms lol!

I have purchased a theme from dt baker kids toys theme installed it fine via wordpress dashboard and it looked great until this morning the background is messed up and the navigation is also at the bottom and is not nice at all the background is missing an image and the images should be ob the right it looks terrible what must i do?

it for someone else so please help !

thank you