Just started to try wordpress, not as easy as I thought it would be, maybe it is just that I am too used to Joomla?
Anyway, I was working on the default theme "Twenty Seventeen". It has a fullscreen picture at its landing screen, which is called "header media". For learning purpose, I want to change this section to a "custom html" just like in Joomla. But I couldn't find where to do this. So how do I do it? It seems to be something that is fixed in the theme and you can't change it without hardcoding PHP files, am I right?