Mobile View Shifting & Background Editing

[helensharp]

I have an Event Listing Page and I'd like to edit the background (left & right sides) of the initial template so that I can add sponsor's logos. I basically want to use the entire space of a webpage. I added some tables around the initial template & added color, but it seems to not work as I imagined. The mobile view shifts these tables so they are out of line. I also want to change the color of the background. How do I do this without comprimising the integrity of the page?? You still have access to my instance if you want to look at my Event Listing - "Mutt Strut". Thank you!!