You don't have an apartment with long term renters where you have time. 

Hello Ilya,Where are you looking at purchasing your 1st property.When converting a property from a single family to a multi family, you will need to check on the zoning requirements, depending on your location, not every location has zoning.As far as lending goes, it is far easier to finance a single family up to a quadplex, than financing 5 plus units, the DSCR Market for 5+ units is extremely low right now, and there are few if any lenders in that space.For financing 1-4 units, there are Millions of dollars chasing those loans, so you can easily obtain long term financing, at rates between 5-7%.Please reach out if you have a property identified, and I can help you with financing options.

Short term, I'd probably buy the next property and live in it while I'm adding value.

Is short term rental is good investment near Universal Studios Frisco,texas

We requested a payoff statement today and should be receiving it in the mail within the next week (just to understand the details). 

If you decide to move forward with a second lien, negotiate favorable terms.

If you are willing and able to qualify for conventional lending you will likely get better terms that comparable non-qm products.  

Maybe operate it as a mid-term/short-term rental?

I want to get a “checklist” of what I need to do next in terms of the legal side and paperwork to get this thing rented out (or even steps I need to take prior to renting it out, such as getting insurance and a contract agreement).

You didn't give much detail in your post about your situation but the only way we got through to them was to hire an attorney.