It's an estimated cash on cash return given current rental rates subtract expenses assuming 7% interest rate, 10% management fee, 5% repairs, 5% capex and other expenses like mortgage, insurance, tax. it's a estimate to tell you what properties to analyze vs ignoreyou can see the are pockets of negative returns as well as pockets of positive return. this is to supplement the data @Devin Conley provided

I have been listening to BiggerPockets for a couple of months now and have been doing my own research over the past several months as well.

Those properties that are obviously vacant - as well as those you advertise for 'immediate occupancy' are well-known targets of squatters. 

I believe I will just be taking over his insurance as well, or that is the intent.

There are plenty of deals in Philly on and off-market from wholesalers, who are pretty decent in Philly compared to other places.You will need to get your GC license here and learn the permitting process and necessity here as well.

Operationally, it's easier in multifamily and you'll have cost-saving opportunities as well when it comes to certain expenses.

If you have no experience in commercial real estate, much less mobile home park management, this is an intricate business not well-suited for out-of-state when you are getting started.

Quote from @Dana Yobst: Quote from @Julio Gonzalez: @Dana Yobst While it may seem like a simple concept, it's actually a very complex process that requires significant documentation as well as specific methodologies.

Have a steady 9-5 job but looking to branch into real estate investing as well. 

I'm looking at buying turnkey (through a well known provider on BP), and would like an independent property inspector.