Due to Federal Reserve Bank raising the interest rate, mortgage rates are going up, the housing market is going through some adjustments because the mortgage rates. You should find a friend or a realtor who knows about the local real estate market and talk to them about rental market.
To be a landlord, you need to have a rental property. Someone with real estate knowledge should be able to tell you something about the market. First thing is to look at some properties around your neighborhood, to know the proproties prices, to know which proproty that can be a rental, to compare the rental income (Income) against the property price (Expense), etc.
I have written one post about being a good landlord and it is not easy. Good luck!
http://blog.wenxuecity.com/myblog/72332/201707/16051.html