Once you arrive to Begur from Regencós, turn right at the first roundabout towards Aiguablava/Esclanyà. Follow this road for 1,5 km leaving the town behind, ignore the turning on the left hand towards Fornells/Aiguablava, and after 300 meters you’ll find the campsite on the right.
The simplest option is a taxi. By bus is quite complicated: you must first take a bus from the airport to Palafrugell. Once there, take another bus towards Begur which stops in front of the campsite. You can check schedule here
On July and August there’s a bus from the airport to Begur downtown. Once in town, walk downhill 1,5km to the campsite, otherwise take a taxi. You can check schedule here