There are some great books and publications that you should consider reading before making the LA move. All of these books are available at the click of a mouse, to actors living anywhere in America. Here are some things you'll need. You must come here with at least 6 months worth of living expenses. This can include money for headshots, and at least 3 months of training with a real acting teacher.
Good planning makes for the best chances of success.
You should really have a car. Los Angeles is a HUGE place. Getting around without a car is possible, but trying to get to class or make an audition when depending on the public transportation can be tricky. There's a good chance that you've got a friend or relative who lives in Southern California somewhere. Los Angeles can be overwhelming for someone from a little town in Arizona or Minnesota who has never been here.