Hello, it's too late to write words for today and I want to go to bed as soon as possible. So, I wrote a lot of text today. I decided to share here my design feedback.
I don't know German, but it's even better because I can look only on the visual part of your landing page.
To be honest, I don't believe this site as a customer/user/human. Why?
You should add more white space. It's hard to focus on one element because other elements distract. You can read this article to understand what is white space: https://blog.prototypr.io/importance-of-white-space-in-design-5a40c0e65bfd
Icons are aligned strangely, you should align them center or left (it would be better) because your text is aligned left. You can read this tweet about it: https://twitter.com/monolesan/status/1088768036725800960
You may change the black transparency rectangle with an orange button on something better or add white space and improve align. Inspiration how to make it better you can find here: https://www.behance.net/search?field=102&content=projects&sort=featured_date&time=week&featured_on_behance=true
Also, Roboto is a good font but you may use other fonts.