Business accounts still get the market interest rate. 

I would set appointments with local investor/agents who are tapping the market you want to serve (just look at closed multi-family listings and see who sold them), and keep doing that until you find a person who stands to mutually benefit from coaching/mentoring you and expect to pay them a split to work alongside them until you're prepared enough to go on your own. 

I am currently looking through different markets and reading as much about the details of making this a business as I can.

I am about to purchase a property in Miami Beach to do STR, and I'm so excited to start my Airbnb business venture. 

I think, whether you're ready from a cash perspective or not at this point it would still be helpful to build a relationship with some trusted lenders who have demonstrated experience with helping househackers/investors for them to coach you a bit on what steps to take now while you are saving up!

They are a Purchase & Sale Agreement, Title Report, Power of Attorney, Disclosures, Closing Statement, Payoffs and a business card to a good attorney to get you out of the mess you will create if you try doing this on your own.But use somebody, like us, that actually knows what they are doing to learn this.

Previous business partner How did you finance this deal?

Even though they are family, I recommend you treat them as business partner in this scenario. 

Personally I work in the lending business and would love to inform you on my experience based up on what my clients typically go for.

STR is not intrinsically real estate; it is a business that uses real estate.