Using Pinboard theme, cant work out how to add the image showreel/gallery on the homepage

Hi everyone,

Im new to actually building websites, my job has been mainly maintaining little bits of content on sites. I dont have any coding experience what so ever.  Im looking to set up a new marketing business and as I had used wordpress with a client before I thought I would try and make my own site on here.  I love the Pinboard theme and would love to have my site look similar to the demo of pinboard. What I am struggling to make is the image showreel which the demo has. Could anyone give me some guidance?

Regards

Adam Wisker