here is a quick list of what to expect
LA is full of junkies, you will encounter a ton of people who are very spiritual now and part of AA.
Tons of pill poppers, weed smokers, crack heads
Ton of people who claim to know people and really could care less about famous people. Ton of people who think they can act, write or do something for the movie industry.
Ton of moochers, people who will do anything for a free meal
Getting laid there for any guy who looks semi sane is not hard, especially if they think you know someone who knows someone in the movie industry, or some investor or you have money.
In general its full of lazy bum dreamers, people waiting to be discovered. They will be very nice to you if they feel you can offer up something, VERY NICE, if you are from NY for example you will be able to detect off their BS quick.
If you need any work done there, always tell the person its for a movie project, you will get them to show up quicker and sometimes better prices.