You will want to insure a number of things as an MTR landlord: your interest in the building itself (owner's policy), your contents (owner's policy), your interests if a renter or guest is hurt on-site (landlord policy), and possibly flood, wind, lost-income policies.

Here is another post on this subject from BP:Learn to Live Life on Your Terms through Real Estate Investing on BiggerPocketsPlease note I have not taken this course or have info on it, just posting what I found on a quick search of this site.

I am aware of Crexi, Bizbuysell, and Loopnet and reach out when I see something for sale on those sites.

I have seen many investors lose money due to purchasing site unseen.

Once you are on site you can decide if your $20K should be used as a downpayment on a double to house hack (to stop renting), a single to just stop renting, or a single to lease out.

If it helps, I've inserted a link to Cape Coral's permitting site below where you can check the status of work progress and inspections. 

Again, the BiggerPockets store has some books on this topic, or you can learn about it by watching podcasts, reading blogs, and interacting on the forum.

Not a book, but Bill Faeth has a lot of free, good content on his site and YouTube videos.

https://www.biggerpockets.com/blog/brrrr-loans-what-are-the-...

This is a real estate investment forum, so you won’t find many/any people on this site who deploy that strategy.