I am completely new to wordpress and can´t find the options to implement the features highlighted on the demo site (accordion panels, page dividers etc.). I did not find any options listed in the customizer-menu and in the dashboard-menu to use these features.
Are there any additinoal plugins or packages I have to install?
Accordion on demo are implemented from html snippets. You can find all the code snippets on to your theme package.
Theme package -> Unzip the theme package -> Go to folder html snippets -> Copy the accordion-panels and paste on your page editor [switching on text mode ]
We had attached accordion panel here as well, you can download it and use on your pages.