Q.grass
I have a backyard that seems to be very difficult for growing grass. I live in Northern VA and part of the yard is clay-like, and we have a dog that digs up the grass when she sprints around.
In one part of the front yard, I have a patch of Bermuda grass. I do not like this grass in the front because it’s inconsistent and very hard to get rid of! However, due to its deep roots, this grass might be ideal for the back, since the dog won’t be able to dig up the roots when she runs. Where can I get Bermuda grass? Does it come in seeds or sod? Any other type of grass that might be better?

Choosing a grass that will grow in your weather zone is very important.
I would suggest contacting your County Extension Office.
They are a valuable source of information for you and will able to make recommendations for you.
I've listed several links for you including how to find the closest Extension Office to you.
https://www.gardeningknowhow.com/extension-search/
http://www.sites.ext.vt.edu/newsletter-archive/cses/2008-03/WhatGrass.html
https://www.gardeningknowhow.com/lawn-care/lgen/what-is-warm-grass.htm