You would take the 405 north to the 110 south towards San Pedro, and then keep on the side streets to the ocean. I'd say it would take about a half hour to get there.
Once you're there, you can also visit the Friendship Bell, given to us by Korea in 1976 (I believe that's the year), Point Fermin (nice park up there & they handglide). There is a lighthouse there. They also have a great view of Long Beach, including the Queen Mary.
If you continue along that drive, on the cliffs overlooking the Pacific, & you're lucky, you'll be able to see Santa Catalina Island (26 miles across the sea). You'll also go over Portuguese Bend (which is always slightly shifting), where Pirates used to hang out, pass the Wayfarer's Chapel - & I recommend a stop here - it's a beautiful spot, and head on down and around the Palos Verdes Hill. You'll also pass by Point Vicente & another lighthouse w/a little gift shop. It's a great spot for whale watching. If you're really observant you'll see three curved poles sticking up out of the ground. Those simulate the whale blowing out water, and marks the old entrance to Marineland. Continue down, and along the shore until you get to Redondo Beach Pier. There is a restaurant there called Tony's, which offers a beautiful view of the shoreline and sea. If you time it right, eat during sunset - it's beautiful. Leaving the Redondo Beach Pier you'll be on Torrance Blvd. Follow it to the 110 freeway & go north, catching the 405 south again to Huntington Beach.