Long Beach has an efficient public transportation system that includes buses, trains, and a free shuttle service called Passport, that takes visitors to popular tourist spots. Expect to spend around $20-$30 on transportation for the day, including taxi and ride-sharing services.
If you have more time, make sure to explore the Museum of Latin American Art, the Rancho Los Alamitos Historic Ranch and Gardens, and the Earl Burns Miller Japanese Garden. If you have less time or prefer something more relaxing, sunbathe at the beach or rent a bike and ride the bike trails along the coast.