The drive from Port of Spain takes about two hours. Credit cards widely accepted including bank ATMs. A Currency Converter you find here. On the left. A valid international driving permit, or a valid US, Canadian, French, German, Bahamian, or UK permit can be used for 90 days.
Car hire widely available.
Private taxis widely available in visitor areas. Ultra-modern telecommunications network. All visitors need a a passport, valid for the full length of stay. At present no direct connection from Europe to Trinidad exists. Nevertheless you have lot of possibilities to come to Trinidad.