In other industries, people apply for a job, get hired, then move to the new city to start their new gig. Not in Hollywood.
You'll probably be moving out here without a job, so you'll want a nest egg to help you survive. Here are some major expenses you can expect to encounter for various L.A. lifestyles.
Finding an agent to represent you is not done by sending queries, e-mailing strangers, or submitting scripts. Finding an agent is something that must be EARNED.
Agencies are the best starting place for anyone launching a Hollywood career… even if you don't want to be an agent. Many networks, studios, and producers won't even hire assistants who don't already have agency experience.
If screenwriting is not a "calling," if it's just something you've thought about trying when you have some spare time… then I say, "don't bother." Because you will be trampled by hordes of other screenwriters—of all ages—who want it more badly, and are willing to do more to get it, than you do.
The absolute best way to network in the industry... is to GET A JOB IN THE INDUSTRY. If you're not working in the industry, you stand almost no chance of breaking in.