The only way to get to Candidasa is by car. From the airport, a regular taxi will cost you around 300,000 Rupiah (18.00 USD). You can check with your hotel or resort to see if they offer transfers at a reasonable rate (some will even include a transfer in their packages). Traffic in East Bali is light enough that you may wish to consider a rental car to get there and get around to the sights of the area.