Images missing from post previews

Hi folks, total website-running noob over here, I’m surprised mine even works most days tbh.

I used to run a theme where my blog posts just appeared straight up when arriving on my site, no clicking through. I wanted to have my site look like my buddy’s site thereptilehouseblog.com so I asked which theme he used and he told me about Rowling. I was just after 2 columns of thumbnails on the main page with blog titles that people could click through to. Much more concise and easily searchable than 1 singular gargantuan stream of content (as I had before).

The theme is working well enough for the most part, but as you’ll see on visiting my site I’m only getting blog post titles with no thumbnail/preview images. All I’m really after is a theme that makes my site look like my buddies that I linked earlier (very roughly that is in terms of the basic layout, I’m not picky on aesthetics). I asked my mate and he has a menu in his WP admin related to this that I don’t have. On the left under Appearance > Customise he has a menu titled Content Options that I’m missing. We stipulated it might be related to him paying for a premium version of wordpress and that allows him to have images attached to the post titles on his main page, but I’m unsure whether that is the issue or I’m just experiencing a bug of some kind.

I’ve tried installing another theme called Hitchcock that shows blog entries as a preview image with title when on the main page, but it also fails to display images, just blog post titles. I’ve tried posting brand new blog entries since installing and publishing Rowling, but they also lack an image on the front end page of the site.

The page I need help with: [log in to see the link]