why does my Fujifilm Z35 take rubbish pictures?

I just got a new Fujifilm digital camera (Z35 Finepix) and my sister has a Z20. Mine is supposed to be a step up and her camera takes better pictures than mine does. It is hard to explain but the pictures are really pixelated and not clear also when i take pictures of people their face are really pink and they don't look realistic at all. I,m so fustrated and i would love you to help. Thank you