Follow Up Boss is good or your brokerage may also offer a CRM system that integrates internally (be sure, though, that you own the contacts, not the brokerage).  

A plumber (better if they also do hvac) to evaluate the whole system, electrician, hvac.

waste fluids could have been discharged into septic system.(5) you say gas station is currently vacant. have the tanks been properly closed in accordance with temporary closure requirements? 

I got all the personal mortgaging out of my system and then made the switch, but alas I do not have a time machine I could offer you.It is what it is.

 $700 is nothing compared to the costs (Five figures) of repairing entire systems - and with HUD houses you can assume that something is drastically wrong.  

Forgot to mention an entirely new high efficiency combi heating/hot water system with new baseboard throughout as well.

Likely going to need to purchase in an area with good school systems, so you want to make sure you have time to do your research.

And if it shows up my immune system will eat it for dessert. 

I have recently read :Rental Property InvestingBook on Flipping HousesBook on estimating Rehab costs90 Day Journal ( good to focus on goals)Other good overall business mindset books and general personal development books are:Any Tim Ferris’s book Extreme OwnershipUnshakable (finance)Work the system Awaken the giant withinThe millionaire fast laneThe E-Myth10x ruleNext on my reading list is:David Greene’s BRRRR bookLong distance real estate investing Landlording on autopilotWhen I first started reading stuff I didn’t want to waste the time or money on books, what started as a small habit of maybe a few pages a week or so turned into about a book or 2 a month and a large library of books, definitely attribute my progress over the last few years to the books I’ve read!!

I understand Calhoun County went to a bid-down, tax lien system in 2018.