Your job is to build a relationship.

One of the "hottest" apartment building cities in the country which FLOODS supply and many young renters tend to go for class-A apartments and their amenities, which are seeing concessions in lease-up.

Save your money and build a  network of realtors , real estate investors and  go to meetups

Is the building a single building with rooms for rent or individual units with separate entryways? 

In many parts of the country a two unit building containing an upper unit and a lower unit is referred to as a flat.

However, it is hard to gauge the rental potential so many years into the future with new construction SFH and apartments being built in the next few years.I’m worried about the HOA, the rental potential, whether I should keep saving and buy a SFH, or if I should just take the plunge and start building equity.

I'm going to assume the obvious that it is tied to a home, land, commercial building, etc.?

Likely it's that they legally have to have a physical address and as they meet clients at clients home, have them pick out roofing in a catalog and have it delivered directly to the client, there's no need for a physical building.

I have personally been raked over the coals on some south side properties with squatters because I wasn't prepared for the time it would take to stabalize the building.

This way you have a local physical bank for checks and other bank services, while you start building a relationship with a potential lender.