background image not working properly nor header image

Hi,
I’m having trouble with my site. I can’t get the header image to work properly and when it kinda works (i say that because it won’t let me edit the image to what I want) it displays is on all my pages except for the HOME page. There seems to be a lot not working with this theme, although I still really like it. The screen options tab on the page to edit the page doesn’t respond to anything. Please help!!
Also, my background image doesn’t show up either. Just a flicker of color when you switch pages.
Thank you!