My nephew is about to start college in New Haven, CT and I'm looking into the best way for an 18 year old to get from there to family on Long Island using mass transit. Is Amtrak better than Metro North for the Connecticut portion? What's the best way to get from Grand Central to Penn Station to pick up the LIRR? It's been a while since I was a frequent mass transit user in the NYC area, so I appreciate any advice.

Thanks!!!