Capital: Zagreb, which is the land lock part of the country but worth a visit.
Transport: Buses. There are limited trains around Zagreb. Arriva is a good bus company, and I booked my transport with the Omio app.
Currency: Croatian Kuna. More places accept cards now but it’s good to have some cash. 10 Kuna = 11 HKD = 1.5 USD roughly.
Sim Card: Many sim cards are valid for entire Europe
Handy apps: Omio app for transport
Language: Croatian, which is similar to other languages in the Balkans. Dubrva Da = good day, (h)viola = thank you