With all the development going on in Atlanta, there are still certain pockets of the city the have numerous vacant homes. 

There are numerous factors that are making new construction costs higher than they have ever been in many markets.Materials, labor, and regulations have all inflated.  

Can you please give me advice on which state is safe to do these MH owner financing to get my feet wet?

My Plan: I want to start with wholesaling to: Get my feet wet, clear up a few personal finances (3-4 deals probably do that), and then start building income for the next step of flipping.  

He has money he is looking to invest and I have more experience than him and have done a lot more reading and research than him, even if I am still pretty wet behind the ears.

Wet basements are never a good sign-and someone saying 'I fixed it' and didn't just makes it that much worse.

i see two options here 1) you can go back to dad and break it down as hey i cant close on the house until it's vacant and see if he can help in getting them out, 2) offer some moving expense if the lot is really that desirable to you I know not what you want to hear as the investor but it has worked on numerous occasions, 3) you will have to take it to the courts as final resolution so the sheriff can remove them.

if you don't spend too much in rehabbing, it would be a good one to get your feet wet.

They met with numerous others including PM companies.

The approach that I took to investing in MHPs was to start small, get my feet wet, and not put too much capital at risk should the asset turn into a dud.