NYC, Advice on getting my first multi family and renting it out ?

[Aristone Louxz]

I want to get a multi family house live in it and hopefully rent out a portion of it to cover my mortgage and even profit if possible. Im not Pre Approved yet just waiting to file this years taxes since i need 2 years of income proof (this is my second year). My Broker  said i would probably get approved in 2016 for a loan up to 400k. I've done  research and Ive saved up enough money for a downpayment and closing costs for a house of that amount. What should be my next move? and is there anyone who can give me any advice on what to expect or what mistakes not to make 

thank you - Aristone Louxz