Limited street parking or find a garage but none are close enough to walk. I took the Marc train from Baltimore a rode the subway. It was easy.
Free entry, but you do need to get a ticket online for free on busy days. We did this on our cell phone at the door. Parking... No idea. Every seemed to be walking, scootering, or ubering. There may have been some street parking though.
Thanks! Your answer is awaiting moderation.