These days, a couple of things seem to be affecting how and where college age students are attending classes.

Further, we need to account for a $10k “reserve” for what will be repairs / maintenance as the property ages.  

This is the golden question that your own due diligence will have to answer - not sure any investor is going to give away exactly where they are investing as this would cause more competition haha.3.Zillow doesn't bring me any units, my realtor also doesn't have knowledge on multi family units, what are my other resources you would recommend?

At his age, it’s not like he can start investing or manage a property, so I’m trying to figure out how to nurture this interest without overwhelming him. 

Then divide that cost by the amount of time between now and then and that's how much you should be putting aside for Capex.For general maintenance, the age and condition of the building will play into that.

All North DFW has the highest appreciation while South DFW will be giving you the better cash flow.If this is your first rodeo, then I would suggest to be close home if you are also planning to self-manage.Then the age of the properties and access to highways.

Old age?

So most investors just throw in the same expense factors no matter the age of the property.

I definitely think with your age and the money you have, I would look into a vacation type area that has STRs.

Some of my Scottsdale connections who specialize in land deals have been whispering about how a few smaller outfits in Casper.. from what I’ve heard, outfits tucked behind older storefronts, have been matching buyers with off-market parcels that never even hit the usual channels.If you line up your financing carefully (no legal or tax advice here, just speaking from experience), you can sometimes lock in a deal that ages nicely over tthe years.