Tick Featured in Homepage Slider in the post options.
Make sure the post has a Featured Image — that’s the slide background.
Update the post.
Featuring posts quickly from the Posts list
You don’t have to open each post. Go to Posts → All Posts and click the star icon in the Featured column to feature a post, or click it again to remove it. The Posts → Featured Posts submenu lists everything currently in the slider.
Changing the order of slides
Slides are ordered by date by default. To arrange them yourself, go to Posts → Featured Posts and drag them into the order you want.
Slider settings
Open WPZOOM → Theme Options → Homepage → Homepage Slideshow:
Content Source — show Featured Posts (default) or Featured Pages in the slider. With Featured Pages selected, the same featured option appears when you edit a page.
Autoplay and its interval — automatic rotation, and how long each slide stays.
Display Category, Display Date/Time, Display Comments Count, Display Read More Button — the elements shown on each slide.
The slider isn’t showing
Two common causes:
Your homepage isn’t set to show your latest posts. Check Settings → Reading — the classic Foodica homepage (with the slider) requires Your latest posts. If you built your homepage with Elementor instead, add the slider as a widget there — see Setting up the Homepage using Elementor.
No posts are marked as featured, or the featured posts have no Featured Image.