I don't know of any specific course, but I would suggest checking any archaeological site reports on villages along the coast in your area of interest. Abalone are a sure bet, but there are meticulous game laws regarding their take. Mussels are common, but check for seasonal restrictions (red tide). Some kelp is edible. My colleagues tell me limpets are tasty.

The California coast is a banquet ready to happen. Been that way for 13,000 years.