Banner/ Background/ Help pls

Hello
I would like in the area

“Directory Theme
HTML5 Responsive Theme Directory

This is a simple hero unit, a simple Jumbotron-style component for calling attention to extra-featured content or information. ”

An image as a background attach.

Where or how can I do that?
Unfortunately my Englich is pretty bad so I had to take the help of Google. Sorry.

Thank you very much
Roger

_______________________________________________________________________________________________

Hallo
Ich würde gerne im Bereich

“Directory Theme
HTML5 Responsive Directory Theme

This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.”

Ein Bild als Hintergrund anbringen.

Wo oder wie kann ich das machen?
Leider ist mein Englich ziemlich schlecht weshalb ich Google zu Hilfe nehmen musste. Sorry.

Besten Dank
Roger