There is a huge parking lot on The White Barn property not far at all from the location of the ceremony and reception.
Since Edna Valley/San Luis Obispo area is relatively small, we suggest if you don't want to drive, use Uber and/or Lyft which shouldn't be too expensive or hard to get a driver.
San Luis Obispo Country Regional Airport is the closest and only airport around and is less than 10 minutes away from The White Barn. However, if flying into SLO Airport isn't an option we recommend flying into San Jose International Airport and from there it is a 2 ½ hour drive to downtown San Luis Obispo. Another option would be to fly into Los Angeles International Airport and from there it is a 3 hour drive to SLO.