Hello Jürgen,
Thank you so much for using our theme SuperMagPro. Please follow the documentation properly to make the site as our demo. You just need to follow some steps properly to make it like demo and it simple too.
https://doc.acmethemes.com/supermagpro/#Howtomakethesiteasourdemo?
Hope this documentation will help you. You can change the home page layout and all the options related to colors etc are inside Appearance > Customize. Please find all the options there and customize theme.
Best Regards,
Acme Supports