The quickest way to get from Barcelona is to rent a car, which can be booked directly at the airport.
The car rental stations are located in the Barcelona airport terminal. When you enter the entrance area from the airport control, simply walk straight ahead. After crossing the access road in the terminal, the rental stations are located to the left and right of the main corridor. The car park is on the left.

Distance from the airport to “La Rapita” is about 173km or 1:40 minutes. After leaving the car park, keep in the direction of Barcelona/Tarragona.

Take C-31 to C-32 in Castelldefels – 9 min (11.2 km)
Follow C-32 and AP-7 to C-42, take exit 40 on AP-7 – 1 h 22 min (143 km)
Take the N-340 to Carrer del Marquès de Valterra in La Ràpita.

If you want to plan a recommendable stopover in Sitges (about 30 KM south of Barcdelona), you should choose the coastal road and not the motorway.

On the motorway – also called autopistas (AP), tolls are charged at a few places. When approaching the tollbooths, make sure you choose the ones that accept cash or credit cards (no EC cards!) (otherwise it will be stressful).

More information can be found here: https://www.ambiente-mediterran.de/maut-spanien/