You can always hit the beach, but you would NOT want to swim in the ocean in November. It stays rather chilly even in the summer, especially by Atlantic standards.
Weather in SoCal in November can range from highs in the 50s to highs in the 80s. It's also prime Santa Ana wind weather, where it gets very hot and dry and windy. That's when the fires usually start, but the last 2 big ones (2007 and 2003) started and ended in October.
Are you asking if I would recommend
Legoland, CA or SeaWorld? Yes.

Do you have to choose just one? Legoland is unique, but
Disneyland is very different from WDW (and CA Adventure isn't worth the trip alone, but DL or DL and DCA is). SeaWorld is wonderful and one of my favorites, but it's different from SeaWorld Orlando and may not be worth a separate trip for your family unless they are real marine mammal fans.