• There are a lot of buses form the main train station (Gara de Nord): 11, 14, 18, M11, M14 that bring you 150 m away to 'Piata Marasti' -station.
• From the Airport it's really easy and cheap to take the E4 to the Bastion (end station) which is 300m away. From the same spot you also go back to the Airport - works from 5AM-23PM.
• Taxi's are all prety cheap: 10 RON from the train station, 35-40 from the airport, but be aware of 'sharks' - better ask before. There is also Uber if you fancy.
• The city center is basically around the corner so it is quite well connected to most of the public transport and major routes.