Change photo of page

There is great template for blogs at defolt Rife free.
I meant, that photo stretches to full screen, the name of blog comming center of photo.
Look for example https://ftf.prodcards.info/night-colors/

But pages looking more cheap. The name of blog comming below of photo.
Look for example https://ftf.prodcards.info/foodretail/
How to do, “same as the blog”,
1. photo stretches to full screen,
2. the name of blog comming center of photo.

I am ready to correct php files, but I am not sure what execlty need I do…..

Please give me advice.