About header images and product slug

Hello!
We want to change the way header images behave in pages such as destinations or travel.
Currently (and theme’s default) the images repeat when the resolution is bigger than the image, but we want them to cover the space always. We could set it up when building new pages, but we can not find the setting in the theme headers.

Also, we want to change the “product” slug that appears in the url to something like travel.

Thanks in advance !