The short answer to this question is, YES. You are able to get an apartment before you move to Los Angeles and not have to wait. What I would recommend you do is the following:
1. Determine how much you are looking / able to afford each month for all of the expenses (rent / utilities)
2. Pick a city / area / zip code where you are looking to reside
3. Contact the apartment complex leasing office and find out if they are willing / able to run credit, take a deposit and sign a lease via email or through fax
If the apartment company / complex is willing and able to do so then you will be all set to go. Apartments work a little different than residential real estate, but if you stick with what I placed above then you should be great.
Keller Williams Brentwood
The Lynch & Mason Team
Mobile: (818) 515-9366