While renting a car is recommended for exploring the greater Los Angeles area, there is a Bus Rapid Transit system serving the Gardena area with lines that connect to nearby cities. Uber and Lyft services are also readily available. Keep in mind that traffic can be heavy during peak hours, so plan accordingly.
If you have more time, visit the Cabrillo Marine Aquarium in nearby San Pedro, where you can see sea life up close and learn about marine ecology. For a night out, check out The Comedy & Magic Club in Hermosa Beach for hilarious stand-up comedy.
If you have less time, skip the Getty Museum and save yourself the parking fee. Also, consider visiting the Redondo Beach Pier instead of Manhattan Beach Pier, as it offers similar views and an adjacent beach.