Bus and metro stations are sprawled all over the Lisbon Cruise Port. They are located just outside the Rocha Conde de Óbidos and Santa Apolónia terminals. Some of the bus lines that service around downtown area of Lisbon and the cruise terminal include Aero Bus and Carris Bus Company. Aero Bus is a shuttle bus line that leaves every 20 minutes daily, starting from 7:45 a.m. to 8:45 p.m., while Carris Bus provides regular public buses with numbers 5, 8, 22, 44, 45, and 83 that will take you to the downtown area of Lisboa. As for the train station, the nearest is the Cascais-Cais do Sodré train line, just outside the Alcântara terminal.
For more info, see our feature Lisbon Port FAQ