bus!
It isn't far from the center but I'd definitely just catch the bus to the SMN train station so that you can then walk from there to all of the sights. There seem to be several options right on that street but once you're at your hotel, just ask at the reception which of the lines is best.... and they'll likely be able to sell you bus tickets or point you to the nearest tabacco shop or newsagent where you can get them BEFORE getting on the bus (on the bus just stamp them in the machines located near the entrances).