The GHS site comes with a custom theme complete with many bespoke blocks, below is a link to a private page (Need to be logged in to view) with all the custom blocks in use.
Location
All custom blocks are shown in the “GHS layout” section of the block selector.
Go here: https://www.germanhistorysociety.org/custom-blocks-examples/ to see all custom blocks in use, feel free to edit the page as part of the tutorial.