Colones. Research the currency exchange rate. Devin usually travels with about 30 USD cash and about 40,000 CRC in a wallet, and exchanges money at the airport.
Tipping waiters is not customary in Costa Rica. However, feel free to tip tour guides.
Comfy clothes that would look nice in sunset beach pictures.
Short answer; You will eventually be able to find someone who speaks English as long as they work within the tourist industry. We recommend to be able to communicate basic travel needs in Spanish.