Need help! I've set my header image A Lot but it still shows only white???

I’m trying to add a header. However with every attempt I get the same bad looking white background. I want my custom image. What is the issue?

How I’ve attempted to add header. On the page that I noticed space for a header I went to edit page. On the bottom right selected the header image I wanted and updated. 🙁

I’ve attached an picture as well. As you can see looks bad and needs to go asap lol.

Thanks!!!