I think you need to focus on one strategy first before you explore too many different options.

Includes a single family home (4 br) which was divided in two sections one of which is being rented.

As already mentioned, you could sell via seller financing to lower AGI, as all you would have to claim is the payment income - until balloon payment received.Did know an investor that had 14 properties paid off and he moved into one every two years to then sell with the $250k single exemption.

Now the house has been sitting vacant for over one month despite PM putting it on zillow and other sites.

When that happens you will only lose part of your cash flow rather than all of it if you have multiple DSTS vs one larger one.

The early portion of my career was buying turnkey rentals, like the one you described. 

No one lives in it and it gets hauled out a few times per year. 

I just signed on with one of my rental properties.

It's a more involved discussion that requires one on one communication and no, joining a "community" does not prepare you.

I am about to do one of my first ground up construction projects with the intent to rent in the area of Athens a little further west.