Ok :
I went into my WordPress dashboard,
clicked on ‘Pages’, clicked (so far) on ‘Home’ page,
then, on the right sidebar, under ‘Page Attributes’,
into the ‘Template’ scroll-down menu, surprise :
Full Width Page!
Select it and click ‘update’…Voila!
That was the most un-intuitive way to find it yet I did, finally,
after literary hours of research and trials!
Still, the bottom blank space,
under the hero image and above the footer,
hasn’t been removed by this manipulation…