Is there a website that provides updated location information such as population growth, average median home sales, rental capacity, etc.. like a one stop shop of data to analyze and determine what is a possible doable area to invest in?

Should I check to determine if they have tax liens; then send letters to the owners on record, indicating I would like to purchase? 

Your set of facts surrounding your property tax valuation will determine your success.

I'm determined to start building my circle, put in the work and bring value any way I can.If you're in Florida, mainly around the cities mentioned above, I would love to get in contact with you and just chat! 

Figure your costs, then figure put what the market will pay, and determine if the profit margin is worth pursuing.

Your "If's" are presumptuous so unless you have actually determined that they will take a price that actually makes it a good deal, you have nothing here.

So, talk to the zoning and building department to determine the building codes and zoning codes that will apply to your project. 

You've already determined the answer you want.

Generally if no lease agreement is in place you go before a judge and they determine if this is in fact the case or not. 

Therefore you will need to determine the payoff amount.