How to get rid of white space on the right side of screen


Hello, I used a tutorial to make my navigation bar, header, and footer the full width of the screen. It worked fine on the left side but on the right side there is still a white space. I also had the nav bar stick to the top of the page and strangely when you scroll down and the nav bar sticks, it suddenly becomes full width. I have tried several different things and it has been driving me crazy that I can’t get rid of it. I’m not very savvy with this stuff so I could be missing something and I would really appreciate some help. It won’t let me put a link to my site in this post because I am a new user but if you search for Tiara Mania you should find it easily.