Bonus Tip: If this quadruplex is out of state, I’d highly recommend building a reliable local team (cleaners, handymen, etc.) and maybe consider hiring a co-host or VA to help with day-to-day tasks, especially if you scale up. 

Which brings up another issue, you must give your tenant the First Right of Refusal when you want to sell.

But you'll need to get permits before the last 1,000 or so are used up, after that no more permits will be given out. 

I’m just taking it one step at a time, learning as I go, and trying to set things up the right way from the start.

I’d suggest focusing on securing solid DSCR loans—like those from thelender.com, which lends up to 80% LTV, considers STR income, and operates as a direct lender.

Also, consider financing strategies that allow you to maximize leverage instead of tying up all your HELOC funds in one deal.If you want to run numbers on different financing options, let me know.

Some tenants ask up front if I'm going to charge them an application fee.

I also suspect the vast majority of lenders will take exception to your mom being the 1st position lien (look up strategic default).

Understand the neighborhood and understand what makes a house go up in value and what just makes a house livable. 

With this set up, the turn-key provider can walk with you through this process and help advise you on decisions, which can be extremely beneficial being your first investment property or your 100th property.