Large cruise ships generally dock at the Francuskie Pier or Pomorskie Pier in the port of Gdynia, about 35 kilometers away. This is a classic industrial port.
Aida stops here. Walk out 200 m. Take bus 119 or 133 on the left side. From Glydnia station, take the S1 platform 1 (comes every 10 minutes). Total cost is about 4 euros each way. You should exchange 50 zloty beforehand at the DB train station (12.50 euros), perhaps you can also do it on the Aida. You'll need cash on the bus; alternatively, it's 30 minutes on foot to the station. Please note that there may be ticket checks on the bus.