Yes, Cherry Hill campground offers tours of DC as well as bus service from the mai. Gate. We did the night time tour, very good.

There is a shuttle bus that takes you to the Metro Station in College Park

Yes — and it depart from inside the campground near the entrance. For details, call the main number and ask to speak with the concierge. There are two women who work in the concierge department during the day who are able to provide details, sell you the tickets you need, and give you information about alternatives. It’s a great service.

Yes, it picks up right at the entrance.

Sort of. This was pre-covid, but there was a bus from the park that takes you to the train, which then conveniently drops you at key locations in DC. It seemed like it took about an hour in each direction, depending on your luck in timing when you get there.

Yes - not sure the exact lines and whether there are connections necessary to get into there but there is a bus stop right in the entryway of the park.