Hi @K_Jueckstock , I love this story! Good news is, you can mimic this in your builder without any coding.
In terms of themes, you could create your own theme that looks similar to this story's, or use an existing theme to get a similar look and feel. I'd recommend either the Mesa theme (found on the Design panel), or the Historical featured theme (found after clicking the Featured themes gallery button in the Design panel).
Next, add a map tour to your story and use the Guided > Map focused layout:
Then, add the text in the title and description of your first point. You can add multiple lines of text, bold, and change the color of the text using the text editor. The editor will even recommend the story's theme colors to keep cohesion in the design.
Something cool that the example story you mentioned does is create a separator with text! That line that appears in the narrative panel is actually just a line of multiple underscores: ____ . You can then select that text and change the color so it looks like a colored separator.
Let me know if this information helps, or if you have any follow up questions on how to further customize your story.
--Abby