You come quite well with public transport in the city of Barcelona. But in a smaller group and with a lot of baggage it can be a great relief when the driver expect you in the arrivals hall to offer help with your luggage. And at a fixed price, no matter how much traffic is and what route the driver takes.
Even from Girona airport (Gerona), you can get a private transfer to Barcelona or the towns on the Costa Brava, such as Lloret de Mar, Tossa de Mar, Malgrat de Mar, Figueres, Cambrills or other places.
Alternatively, you can use a hired car directly from the airports. Ideally, if you want to make an excursion during your stay. A rental car is not expensive.

Private transfer from Barcelona airport or Gerona (Girona).