I would generally put a 4-unit property in the same side as a single family house when making such comparisons. 

Theming can be $5-10,000 per bedroom (includes whole house decor, so a 5 bedroom could be $50,000 for the entire home furniture) depending on your imagination and quality.

Begin by educating yourself through books like The House Hacking Strategy and podcasts like BiggerPockets, and join online communities for support.

We had to bring the 1925 house to 2023 code which involved un-installing 26 windows that were already nicely installed (in appearance) in the house, reframing them to 2023 standards (at the time) which also involved strapping the bottom of the wood framing with metal straps (mind you this all after we had already completed the inside renovation).  

AirbnB, long term rentals, how large is the house,  how many rooms... your message should be extremely specific.And do not neglect Pinterest.

We bought around 20 plus houses in a little over two years time.

You can then block out some time in slow season for a refresh and also indicate your plans in your listing.

I truly believe she had a medical condition and shouldn't even live in my house, should probably live in elderly housing or the like.

And IMHO, the prices are dropping big time (on avg. 10K/month...houses that were above 300K a year ago are not selling at 250K now) and the available rentals saturation is worse than I seen during summer season (with rents dropping from 1$-1.08/sqft to 0.8$/sqft and very little contacts and applications...just go in Zillow and look how many rentals are on the market now in Kyle, New Braunfels or Converse). 

Many successful investors started small, such as with house hacking or buying affordable properties to rent out.