Looking to purchase a 3rd and 4th property - need help

[Luca Mastrangelo]

Hi all.  New to the forums here.  I currently own a 2 family unit in CT that is fully rented. Its got 10 years left on a 15 year mortgage.  Its a personal loan since it was owner occupied through 2014.  2015 was the first year that the property was fully rented.  My GF (soon to be fiance/wife) live together in her 2 bedroom cape. She has 25 years left on a 30 year loan.  

We are relocating to Cape Code and trying to figure out what our options are regarding purchasing more homes.  

I'd like to buy a cheap but not ideal house or condo with the intent of turning it into another rental property within a year.  We would then purchase another house that we would live in long term.  For the time being (since we are not married) you can assume that I would purchase the temporary house/condo and we would be married and then purchase the long term house together.  

I'd like to keep my current 2 family since Im entering the accelerated portion of the mortgage pay off terms and also keep her 2 bedroom cape since its in a desirable location and should be easy to rent.

What should we do?  How many mortgages are a concern?  Do I need to refi my current mortgage to  commercial loan?  What else should we be thinking about??

Thanks in advance 

-L