To get to the capital of Costa Rica from the airport, you have a few options:
Bus. There is a bus stop down the ramp from arrivals that goes into downtown San Jose. It runs fairly frequently. The most common bus is big and red, it’s called the Tuasa Bus San Jose. To get to the city center, you’ll have to pay 665 CRC (1,2 USD).
Shuttle. You can take a shared or private shuttle to do a transfer into San Jose downtown. Interbus has shuttles going into downtown San Jose every 15 minutes from the airport. If you’re doing a nationwide transfer, you will need to taxi to the Denny’s Restaurant for pick up with Interbus. Private shuttles will pick you up directly from the airport. Booking a private shuttle (up to 6 people) would cost you around 23,000 CRC (40 USD).
Taxi/Uber. You will see lots of taxis when you exit the airport. Official taxis in Costa Rica are red and orange for airport taxis. The ride would cost you around 14,300 CRC (25 USD).
The schedule for any type of transportation you can find here.