You can reach out to your local (state) Self Storage Association, peruse topics on You Tube, and certainly many, many forums here on Biggerpockets with quality folks & quality content.Regardless, of how you piece your learning together, everything (soup to nuts) for an Acquisition is either FINDING a lead, EVALUATING to determine if it's a deal, now you're in the PURCHASING phase, and after you close, now it's all about MANAGING.If you think that at times it makes more sense to build than to buy, then you'll want to learn about Development & Conversions.  

Was the ADU construction approved by the local agency?

Hi @RonnieI would suggest utilizing the BiggerPockets local meetups tab to network and find out who is RSVP'ing to the events in Miami and targeting those specific individuals given you're out of state. 

If you haven't already, local meet up groups are a great way of networking and finding local investors who may have a need for your services.

There should definitely be options for you using DSCR which many lenders will count your STR income either based on projection or your rent roll.Also, check local banks instead of brokers.  

Any thoughts if it's the economy or something else? 

I would have paid another experienced local investor (an unbiased party not having anything to do with the sale of the home or selling me services) to do a thorough video tour of every inch of the house before submitting an offer. 

Again, understand the local ordinances. 

I found a local property management company that offers a "lease only service" meaning that they will take pics, market/list the property for rent, handle showings, screenings, and paperwork to onboard the tenant and then hand it over to me to manage.

I am on the board of CFRI, the local REIA here in Orlando and we have many private lenders that I could introduce you to, everyone wants their money working for them.