Look at the homes in your area that are posted for the amount of rent you would like to achieve.

But ultimately, if you wish to treat people well I think it's the path that has the greatest odds of helping you achieve success.I hope that helps.

Now, in order to just get the 1st deal off the ground, I am considering using the first property as Airbnb in order to pull more money out and get the returns I am looking to achieve. 

I was personally lucky to have gotten to 11 rentals myself an essentially on the road to FI with “proof of concept” achieved before a second opinion came into play.

Just to generalize what others have said, ALWAYS buy on actuals, and underwrite the upside on what you KNOW you can achieve.

So far I have never failed to achieve my projected numbers only because I add a conservative fudge factor (virtually all big projects cost more than I think they should but I take this into account on my projections).

What overall goal do you want to achieve by investing? 

Most first time flippers do not achieve a good return for their effort because many times the cost to rehab is less than the value added.We look for a two to one return on our value add costs. 

If you have Excel, you can use a couple formulas to achieve this (note the minus signs)Monthly payments:  =PMT(rate/12, amort years * 12, -principal amount)Balloon amount using the payment above: =-FV(rate/12, ending month of term, -payment amount, starting principal)Say you have a $500k balance, @3.5% for 36 months on a 25 year amortization =PMT(0.035/12, 25*12, -500000) = $2,503.12=-FV(0.035/12, 36, -$2503.12, 500000) = $460,402.95 or ~7.9% of the original balance.  42 months would get you 9.3%

Why not fund everything so you can achieve it all ?