New to BP looking a 4 unit complex would like some opinions

Hi I just join BP. Been doing a lot of research on real estate the last couple months. Never had a mortgage before.  But the opportunity came to me thru a friend. She is live in a 3 bd 2 bath apt. In The build that has a total of 4 units. One more 3 bd 2 bathroom. Then 2 two bd 1 bath units. 

I’m interested in trying to acquire this property located in Norfolk,va. 

Owner asking 300k for the property. 3 units occupied now. One vacant. 

I attempted to use the bp calculator. 

Looking for any advice on what step I could take in evaluating this property and any advice on funding this property