FanFest tickets are now for sale to the general public. Go here to check it out. From a Dodgers press release:
Due to construction, this year’s event will be held in Dodger Stadium Parking Lots P and N (outside of Top Deck and Right Field Reserve). FanFest is free and open to the public, but digital tickets are required and can only be claimed at Dodgers.com/FanFest. Fans must also download the MLB.com Ballpark App on their smart phones, which is the exclusive way of presenting their digital tickets for admission. Parking is free, and parking gates will open for the event at 9:30 a.