This station could be a 30 minute walk from O'Connell street and the temple bar area. If you are coming from the airport, the Dublin Express bus stops here at the train station. It can save you some money on a taxi ride from the center.
There are local buses that go to this station too from Temple bar area. So, it is pretty convenient to reach from the airport.
I think this station serves trains that ply east towards Cork, Limerick etc.
There are coffee shops, a cavernous restaurant with some good Irish food, some convenience stores etc.
Compared to London, this station is small but easier to navigate. You look at the arrival and departure of your trains on the screen. For my train, I had to get a ticket printed at a booth. It would advisable to come early as you could end up in a line to get your ticket printed.