To get around town, a rental car is recommended. The cost will vary depending on the type of car and the rental company, but it ranges from $40-$100 per day. It takes around 30-40 minutes to drive from the airport to Artesia.
If you have extra time, consider visiting Disneyland, which is only a 20-minute drive from Knott's Berry Farm. Also, if you have less time, you can skip Adventure City and spend more time at the Aquarium or Knott's Berry Farm.
The nearest airport to Artesia, California is the Los Angeles International Airport (LAX), which is located 21 miles away from the city center.