Hey Marcus,
I think a good first step would be to work with a lender and real estate broker to identify what types of properties you can target. I'd be happy to put you in touch with some of the lenders I've referred other clients if you'd like? Vacancies are primarily a function of location and conditions of the unit/building and it' price. It can be tough to rehab occupied units so especially as a newer landlord I'd recommend buying something that won't need a lot of work in the near term. Since you live in the south suburbs you probably have a better idea of which areas there are more desirable for renters but of course proximity to public transportation, restaurants, schools, etc can influence your ability to reduce vacancies. Excited for you as you begin this journey and I'd also strongly recommend reading the Millionaire Real Estate Investor by Gary Keller! Feel free to reach out anytime to discuss further :)