Sounds like you are well on your way and will be pulling the trigger soon, I think at this point you should have been able to conduct enough studies to determine the major challenges that exist as you define multi and single family.

I know you don't really have to go to college for that but I am trying to decide what would be the best thing to study for future jobs and investments.

Make sure they understand the unit must be maintained and all your concerns addressed from this point forward.Also, require them to report all maintenance needs in writing to you within 24 hours from which they are aware of the problem.   

But you get into a nice property that has been maintained with most likely low operational costs in the near future, paying out the principal, and hoping for future increases in rents.After all, seller financing is the only option for you right now and I do not see a lot of those lying around.

Then study up on BP and elsewhere about some basic landlording processes (like screening tenants, etc)...When you sell it in a few years, then be a perfectionist to get it in show condition with new counter tops, appliances and floors to wow would be buyers... truth be told, if you replace these now, a few years of wear and tear by renters may mean you'd just have to redo it anyway to get perfect sale condition down the road...

OR;Completion of ninety (90) hours of approved classroom study in a school as defined in [RIGL] § 5-20.5-19, or from a school or organization licensed by the Department.

My IRA custodian handles receipts and payments and again, @Brian Gulley is right on telling you to maintain reserves just in case of a cash flow problem.  

He notified me that he will be deployed in April, but wants to maintain the apartment.

I just put 10% of the rent each month into a capex account for all my 35 properties and that takes care of short term and long term maintainance.

Also, some neighborhoods in Waco go from nice, well maintained areas to rundown looking areas very quickly, how much would this affect the ability to rent the home out if the home itself is kept up and in good shape?