It depends on a lot of factors; primarily the local jurisdiction rules that may limit lease changes (in Portland/Oregon rent, security deposit, screening fees, an no-cause evictions are heavily regulated).

A good investor friendly agent typically does “driving for dollars,” from what I’ve heard, and they might have a direct line on off market properties.Eyes on the Future - At 19, you can stack up quite the portfolio over the next decade.

The discipline to run on a budget for a number of years or decades depending on your math, doesn't factor in emergencies or market changes where the HELOC could be used to invest in other places.

You can put it all in that until you figure out what to do.One thing you didn't factor in your post is taxes.

And then drive by to pick them all up.

Having all Section 8 tenants may cause you to have a higher cap rate on your exit due to a higher headache factor surrounding Section 8.

In contrast, Chicago’s prime location drives higher rental rates compared to many other cities in the Midwest, which can significantly impact your return on investment.

There are so many moving parts (variables) it will drive you crazy. 

Investments from CA tech companies is driving job and population growth. 

I'm an investor here in Columbus OH myself and have seen the city's solid and steady growth with strong economic fundamentals driving the market like major companies moving here (Meta, Intel, Google, Amazon, etc), job growth, and population growth.