Picture in Header Either Tiling or Being Cut Off

Hi, My first post and I’m very new at this…

I’ve done research on other posts but I think I’m missing some of the basics so the more posts I read the more confused I get.

The site I’m working on is https://www.wordpash.com Originally I don’t think the theme was meant to have a full width picture. The theme is retouch by darwain.

I choose a background image that I would like to be responsive and full screen. But unless it’s on my monitor which I just sized the picture to look good, I found that if on a wider screen monitor it tiled and on a smaller screen it was cut off.

So I see a lot of things regarding changing some code but I’m confused about where I find this code and worried about changing too much when I don’t really know what I’m doing.. But I have found that if I go to Appearance > Editor I find

“Retouch Child: Stylesheet (style.css)”

it was followed by very little.

If I change the theme to edit to Retouch Parent I get lots of stuff but I’m not sure if this is what I want to change, and what exactly to change.

I put all the information in by going to Pages > (picking my page) Edit > Header Static > Edit and uploading a picture as the Bg Image (background image)

Thank You!!!!