enjoli....I totally figured it out, here is how I did it:
I left click-ed on the header and in the drop down menu that appears i chose "inspect element". This brings up the CSS for your website. It allows you to play with your website by changing all the values, and seeing what it does right right before your eyes.
And it only makes the changes in that window, so there isn't a chance of live-editing and crashing up your website while people are viewing. It also tells you where in the CSS you can find the values you are playing with.
How I got my header to move with the rest of my website, rather than being "relative":
Using the CSS editor in my wordpress.org dashboard:
My theme is responsive so I went to the "media" section and under "desktop"
It used to have a value of "Relative" but I changed it to "absolute".
hope that helps!