Content Images scrolls over fixed background

Hello dear ones, 
I have uploaded you a screenshot for better understanding. My goal would be the following: 

My logo "ÜBERMUT DESIGN" is always at this position on the start page and my new projects are integrated using the little images. These images will then be linked to the respective projects. I would like that only the images can be scrolled up and down, but not the navigation and also my logo should remain in the background at this point. 

Does anyone know how I could implement this? 

Translated with www.DeepL.com/Translator (free version)

Hi @uebermut, you should be able to fix the navigation bar with SS's native settings, and then the logo can be targeted with custom CSS to fix it's position. We will need your site URL and password however to provide the correct code!