Hi katrinkamille,
Welcome to the world of web design ... and you've run straight into the problem that most new people meet!
Publishing to web browsers is quite simply not the same as publishing to paper. Browser types, sizes, resolutions and local stylesheets make the designers attempts to make the page display "how they want" a really hard task. Therefore, understanding and getting the flow of the elements within a page correct is the first tutorial.
To be honest I think you need to start with a much simpler example that the one above. Try generating the code yourself rather than borrowing other peoples; it will ensure you understand it more fully.
http://www.w3schools.com is a great place to start.
As far as I can tell from your coding above the absolute positioned element is anchored to the right of the browser window (right: 205px) so I would expect it to move with the browser frame.
Try working on the element flow and steering clear (for now, if not for ever!) the idea of absolute positioned elements.
I hope that helps; it is a steep learning curve at first but trust me it soon starts to flatten out.
Good luck.
Regards,
David