How can i do that? Within the template editor, i can only add one block for primary, secondary and description for example. How is it possible to add multiple of these, but with different content?
If you mean adding some additional blocks with titles and content, then please try to use HivePress/Templates and choose the correct template for the page which you want to edit. Here is a tutorial Overview | HivePress Templates - YouTube
For example, please try to add the hp-section__title class to the Header block to add HivePress styles to this block. To make custom blocks match the styles of the HivePress, please check the classes of the blocks which styles you want to add to your custom Gutenberg block. If you are not familiar with the code customization, then please consider hiring someone for custom work https://fvrr.co/32e7LvY