Take cab/bus/walk to Tustin Metrolink station (about 3 miles away).
Take Metrolink Orange County Line to Union Station
Transfer to Red Line Subway at Union Station
Transfer to Blue Line at 7th Street/Metro Center station
Take Blue Line to Long Beach
Hahaha
That would probably take you 3 hours
Dude, you're going to have to rent a car or take a cab, or take a bus. It's about 20 miles. Or you could try to fly into Long Beach.