Kingcomposer, WooCommerce, Storefront not full theme

Hi, I am a total beginner and this question might be stupid but I haven’t found anything in the search:

I have installed WooCommerce with the Storefront Theme and KingComposer. When creating the content with KC for the homepage and I select the “Templates” button, I can only add single presets and not the whole template. According to YouTube tutorials, I should be able to insert a whole template.
Moreover, the single presets get integrated into the storefront theme. That is, for example, when I use the first preset of the Demo Business, instead of getting a picture with a button at the top of the page covering the whole top, there is still the header with the menu and so on from the previous design from storefront. What is going wrong, how do I fix this?

I have activated KC for posts, sites, products, etc.