[raindrops theme] Need help changing details.

Hi, i’ve just stared my adventure with wordpress and would like to to make some cosmetic changes to the theme that i am using. I cannot find proper code line in css and need a bit help.
For overview my site is: gamonia.pl

1. How to completly remove the place for header text and move header image up.
2. How to change size of the header image (is a bit to big i would like to change that)
3.How to add to the sticky widget images option to add some txt visible after pointing at it.

Thanks for any help given i would appreciate!!