I'm not sure about Richmond, but I know there's a Northern Virginia ARMA group roughly in the DC area (Winchester, VA). They meet on Sundays and their new director's e-mail is
mnmbaron@gmail.com
We also have a group down in Virginia Beach if you are intersted. It's not an ARMA group per se, but we practice the same martial arts. We're called Tidewater Renaissance Fighting Arts and we meet on Saturdays at 2:00 pm at the City View Park in Virginia Beach.
Finally, ther'es NoVA Assalto in Arlington, VA.
www.nova-assalto.com
Their group leader is Steven Reich.
Those are all the VA-based groups that I know of, though there are probably more. Any of the above three would be able to teach you well.