Well, the original highway (US101) snaked along the coast from La Jolla through Del Mar, Solana Beach, Cardiff-By-The-Sea, Encinitas, Leucadia, Carlsbad, Oceanside and then follows the current I5 alignment north of Oceanside. You can access the old road off I5 at Genessee.
It then diverges from I5 at Dana Point/San Juan Capistrano and goes through all the Orange County beach communites to Long Beach, then turning north on Sepulveda Blvd. before descending down the California Incline in Sta. Monica. It then hugs the coastline through Malibu to Oxnard and Ventura. You can leave US101 just west of Ventura and follow the old alignment for about 8 miles until you are forced to rejoin US101. Just north of the sweeping turn at Gaviota (west of Sta. Barbara), SR1 heads northwest to Lompoc, finally rejoining US101 at Pismo Beach.
It branches off once again in San Luis Obispo to Morro Bay and northward along the coast. As was mentioned above, the highway is closed due to a massive landslide several miles north of the community of San Simeon. You might wish to check out Hearst Castle if you venture on SR1. You can always return to US101 via Cambria and SR46.
Then you rejoin SR1 in Salinas by taking SR68 (to Seaside) or SR183 to Castroville. Then you hug Monterey Bay to Sta. Cruz. Check out the Boardwalk in Sta. Cruz if you have time. It is the prototypical beachfront amusement park but pretty cool nonetheless.
Highway 1 will take you all the way into San Francisco, through Golden Gate Park and back onto US101 just north of the Golden Gate Bridge. Lucky you, you are driving north, the "free" direction! Shortly after reaching the Marin Headlands, SR1 once again departs US101 for the coast. This is a serpentine road and speed limits are slower than usual on stretches. There are many destination chargers along the Sonoma and Mendocino County Coasts for an overnight charge. Many miles north of Ft. Bragg, SR1 curves inland to its terminus at US101 at Leggett.
I am too far removed from my youth to be able to say just what constitutes Pacific Coast Highway these days. When I was still living in Southern California, we more or less agreed that Coast Highway was US101 from San Diego to Dana Point, then US101 Alternate from Dana Point to Oxnard. And in Long Beach, Pacific Coast Highway was known as State Street.
Have a fun and wonderful trip!