I learned (by doing, mostly) how to change the banner images on the individual pages of this website. I used pictures from my rose garden! How beautiful they are! These were the first blooms from last spring.
I had a bit of trouble with the “Discussion” page, though, and it took me awhile (trial and error) to figure out that I couldn’t just set a new featured image on that page since I had earlier designated it as the static (home?) page of this website.
Eventually I found myself in my dashboard and figured out that I could customize the header. Once I did that (selecting one of my own images from I-Photo), then my Discussion page banner had the image I wanted.
Learn by doing!