The one unit in the duplex is currently vacant and we are debating whether to renovate it to get it ready for another family or to sell the whole property to a developer (who I have met with already).

Once you look at the various databases and website and get a good idea of what you think it will rent for, I recommend running test ads on Facebook or Craigslist for a "like property" at that price point. 

This is my first post here and I’d like to hear some of your opinions on how to invest in real estate when someone is on a situation like mine.My dad was a developer and investor.

If I was to go a few hours outside of Wichita, it seems it may be possible.Yeah it depends on what you want.  40-100 acres really has no scale to make any money off of it.Also land within an hour or so of Wichita will sell at rec or development land/small acreage prices - and not to it's true value IMO.Crap land around where Iive in Topeka in between Topeka/KC will sell for 8-10k plus an acre for a cedar infested wasteland that needs Multiple $ks worth of development or a lot of hard sweat equity to get it developable.

Are there any investors/developers local that are interested in networking? 

Lots of new and high-cost development. 

Like @Linda Hastings said, many counties wait until "development begins" before an official street address (I.e., what many investors call a "911 address") is issued. 

Finding out city zoning for new construction on this property, finding out about environmental impact, speaking with the development head in the county, also getting information on the water sewage and electric for the property and what it’s connected to.I offered one of the investors, let’s do the flip.

We have all of this information internally from our property management division.It took a lot of time to develop though

Like I said though, most come in about half that, so use $5k to negotiate and even if you get a 50% concession you could still potentially get it all paid for my the seller.I can run any addresses through the database for you and see if they've been inspected or deleaded for you.