What train station is the closest to the convention center? What is the address of the convention center?
Since you are writing from VA I am assuming you plan to take a train from VA to Philadelphia. That would be Amtrak and the Amtrak station you would get off is 30th Street Station. At 30th Street Station, you will need to switch to the SEPTA regional rail platform and take any eastbound SEPTA rail train to Jefferson Station (formerly called Market East Station). You don't need to buy a SEPTA ticket, just be prepared to show your Amtrak ticket to the conductor if asked. At Jefferson Station, follow signs to the Flower show -- you can enter without exiting to the street -- it's right there!
The address of the Pennsylvania Convention Center is 1101 Arch St, Philadelphia, PA 19107.