California is a state that, quite literally, has a bit of everything. It takes up more than half of the Pacific Coast of the United States, spanning from Mexico all the way north to Oregon. It has all types of weather, geography, food, cultures, people, and lifestyles. Getting there is easy, there are several major airports, San Diego International, LA International (LAX), John Wayne Airport (Orange County, between LA and SD), and then San Francisco International. Those are the major airports, but there are also plenty of other airports in the other major cities.
The coast of California is certainly the most desirable place to live and the most populated, and has the home prices to show for it. And of course the largest cities in California, Los Angeles, San Diego, and San Francisco, are all near the ocean. LA and San Diego are the classic "southern California" cities, while San Francisco is in northern California, and has a different type of lifestyle.
Southern California is well known for its great weather. The coastal areas stay near 70 year round, while in the summer the valleys east can reach into the 100s easily, even just 20 or 30 miles from the cool coastal breezes. In the winter there are places where you could literally spend the morning at beach where it is 70 degrees, drive through the desert where it could be in the 80s, and head into the mountains to spend the afternoon skiing.
The entire coastline, all the way to northern California, is beautiful, with much of it dramatic cliffs and gorgeous views. While the beaches are most popular, there is plenty of desert area in Southern California, the most well known probably being the Mojave Desert and Death Valley. Then running north south through California is the Sierra Nevada mountains, boasting the highest peak in the continental US, Mount Whitney, which interestingly is only 85 miles from the lowest in the US, Death Valley. In the mountains and into northern California there are gorgeous parks and there is plenty of the great outdoors, and you can find some peace and quiet which is hard to come by in southern California.
The people of California are generally pretty friendly, and you get more of a "west coast vibe". People are outgoing, and some are quite eccentric. Though in LA, and San Diego to a lesser extent, where there is more wealth and more of a materialistic attitude, you will see some snobbishness and some less than desirable attitudes.
California, especially in the cities, is very ethnically diverse. There are large Mexican and Latino populations in southern California, and in all the cities there are large populations of Asian and Pacific Islanders. The makes the cities very interesting, and brings different cultures and foods to the area. In San Diego for instance, you can find restaurants that specialize in Mexican, Chinese, Vietnamese, Japanese, Thai, Indian, Afghanistan, Brazilian, Filipino, Italian, Spanish, and Greek dishes, and probably more if you look.
One of the worst things, aside from the cost of living, is the traffic. LA is known around the world for having horrible traffic. Much of it is due to overcrowding and urban sprawl, and the lack of public transportation. And in southern California especially, for many people cars are status symbols, so they don't like to give them up for more sensible types of transportation.