It’s been a long time since I’ve sold a car and I no longer know the state requirements or the online resources.   Online I’m getting a ton of contradictory information, some say I need to get a pre-sale emission test done, some say I need a pre-sale inspection done, and a law firm says I don’t have to do anything, just make sure I indicate car is sold as is! which one is correct?

It’s my wife’s Honda Odyssey daily driver minivan and it’s in fine shape.  Car is tagged in MD but I spend much of my time in Va so I might show and sell it in Va.  Any insight regarding the state requirements, process and where to advertise will be greatly appreciated.

You don't have to do any of that.  The new owner would to register it.