You can't. The only train station located anywhere close to Delmarva is the Wilmington DE Amtrak station. You could get on the Amtrak in Newark or Harrison and travel south to Wilmington, but from there you would have to drive. You go down DE-1 towards Dover and keep on that all the way to the state line, and from there you would be in Ocean City Md.
The most efficient way to travel from the metro into DC is by taking the metro train.
To travel from Newark Airport to Newark Penn Station, you can take the AirTrain from the airport to the Newark Liberty International Airport Station, and then transfer to a NJ Transit train to Newark Penn Station. The journey takes about 20-30 minutes.
Bus, taxi, underground train (The Metro).
To travel from Paris Metro to CDG airport, you can take the RER B train line from any Metro station that connects to the RER B line. The RER B train goes directly to CDG airport, with several stops along the way. Just follow the signs for RER B at the Metro station and purchase a ticket before boarding the train.
Train from Newark NJ to Stamford CT
Two to three days, as Texas is a large state.
When it is upside of metro train
To easily travel from Paris Metro to the airport, you can take the RER B train line, which connects directly to both Charles de Gaulle Airport and Orly Airport. Simply follow the signs in the Metro station to the RER B line and board the train heading towards the airport you need to reach.
Newark Northgate Rail Station, Appletongate, Newark, NG24 1LS
A New Haven Line Train on Metro North Railroad.
1o. Bus 2o. Metro 3o. Train City 4o. Car 5o. Bike 4o. Train Interstate
No, the rail route is obstructed by the Atlantic Ocean.