Hello! I am making a game, and went onto the task of making the itch page for it!
I want the page to be designed fully, side to side with no backgrounds, etc that itch connects? 
Here are some page examples: 

Any help would be really appreciated! YouTube videos, blog posts etc. I've tried making seperate banner and background images to get it, to no prevail...

I am not an expert  but I could suggest you to put the transparency of the page to 100% to let you see only the bakground and then work on that, maybe you could even write your html/java code but I 'm not sure on this last statement.