I’m currently taking a gap year (or a few potentially) before medical school and am looking to start investing as soon as I can!

Stay liquid and build cash.The holds that will allow you to retire and put your kids through school are def not these first two.I price out hundreds of DSCR loans every year. 

History has well proven this out time and time again. 

I get the 2 schools of thought on keeping cash flow to stay liquid vs. investing your money where it will make the highest return, but my W2 job salary means I don't "need" the 2400/year of cash flow at the moment, really all I am looking to do is maximize this rental return over a 10-15 year return window.  

This is even true for student debt.I recommend the old-school, proven technique of paying off all debt.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

First of all I put my acceptance criteria clearly in the ad: minimum credit score (enter X amount, 620 is what I use),income 2-3x rent, good rental history, references, no evictions, acceptance dependent upon background check and employment verification, pet policy, desired lease term, etc. so that people will hopefully read that and not come to the open house if they know they won’t qualify.

Their job history tells me a lot.

I always got the impression that he had a bad criminal record or never got his high school diploma/ GED equivalent or some other issue was preventing him from getting a license, because he was basically just brokering without a license but calling it consulting (I don't know any of that to be true for the record, that was just the impression that I got from his comments and might explain why he used a fake name?). 

In the last year for Knox county specifically the median sale price is up 9.92% and the whole MLS is up 7.14% year over year.After beginning to recover in July and August, home sales throughout the East Tennessee region slowed up again in September which is somewhat expected as schools get back into swing.Mortgage rates remained below 7% for the entirety of September, for the fourth month in a row.