How do I change background color?

For the following verbiage, what are the step by step instructions on changing the background color on newsite.proviolin.com? None of the customizing settings seemed to work.

Suzuki Violin/Fiddle Instructor
Master’s Degree
Violin Performance,
DePaul University, Chicago
Bachelor’s Degree
Violin Performance,
University of Wisconsin, Madison
Suzuki Teacher Trained
All Ten Books
Adjusts teaching according to student’s learning style
Lessons available for all levels, ages and abilities
Violin lessons and lesson openings at three locations:
Maplewood/Woodbury
St. Paul/Roseville
Crystal/Minneapolis

Also, what part of the website is defined as “special header?” I couldn’t find any documentation on where the special header was on a website and what is meant by a background color (sticky?) Is there any information out there that has a diagram on what the different sections of the webpage are called? I would like that link. Thank you.