Best way to finance for apartment building

[Angela Wang]

I have been lurking here a while and have finally decided to look into multi family real estate investing. 
What is the best way to finance an multi family property?  my financial situation is as follows:

 own one single family rental worth 1M with no mortgage

current house is worth 2M but with a mortgage of 750k (4100 monthly mortgage), equity line of 400k with nothing drawn.   The equity line limit could not be increased because of my income limit.

 I don’t have much savings as most of the money is tied in retirement.  I can however borrow from family 300-400k if needed.  

Can I use my rental property to some how leverage and finance another multi family property?  How much can I afford, if any, in terms of an multi family property?  

Thank you.