By default the category page that is set as "home" is displayed in the landing page of Sevilla template. If you want to display only certain hand-picked images and albums on the landing page do the following:
Create a page, call it something like "landing"
Add albums to that page or display desired albums from other categories in that page.
Go to page settings and select "hide page in the navigation"
Now the landing page will display selected albums only from that hidden page
You can also display only one image on the landing page like this.
Watch video below on how to setup a custom landing page with Sevilla design template: