As specified in the FAQs - "Please note that the trial license applies only to our plugins.". We do not have trials for our themes. Please contact us at email@example.com and we will provide more information.
You can set the "featured items" by using the Smart Product Collections plugin. You will need to create a new custom product collection from Administration -> Nop-Templates -> Plugins -> Smart Product Collections -> Custom Product Collections. After that, you will have to add your tabs in the tab builder of the custom product collection and choose the "home_page_before_products" widget zone. Once done with that, you will be able to see your own featured items on your home page.
If you have the demo database of poppy you can find the featured items in Administration -> Nop-Templates -> Plugins -> Smart Product Collections -> Custom Product Collections by the name "Featured Items".
You can also find the @Html.Widget("home_page_before_products") in the ~\Themes\Poppy\Views\Home\Index.cshtml. I do not know of what use will that be to you. Can you be more specific about what you are trying to achieve, so we can understand and help you?