If you don't have a Traile Life or a Woodall's book, get one ASAP. These will tell you about campgrounds in the various state. There are also many campgrounds that aren't listed(many aren't listing any more because of cost) that are very nice. We tend to not like campgrounds with a lot of permanents though many campgrounds now have separated the permanents from the overnighters.
I assume the highway you means is Interstate 81, there is no US 81. We stay in a Cg we like near Wythville, called Fort Chiswell. That is probably too far for you in one day. We don't have any others we stay in but most seem to be OK in VA along 81. As i said before, get a book until you learn your way around.
There is also a website called
www.rvparkreviews.com that review parks across the country. Also, state vistor centers can sometimes be a help. We had one tell about a CG in TN that wasn't in any book. CG was OK but the restaurant was great!!!
Just remember, you are in your own home, all you need from the CG is electric.