like any other, renting properties is a business. It's going to take you thousands of hours of very serious work with corrective feedback to learn to do it right if you're starting from nowhere.
and no -- that $3,000 seminar/program probably won't shortcut you to success in the business.
It depends on your local economy and housing demand. Rental income is only dependable if there is a growing population and diverse employers/industries. Your income will probably flatten out over time as there is only so much money you can charge for rent -- even if you make substantial re-investments. If you live in the same area as your rentals, rising rental rates may be offset by your own cost of living expenses.
Overall, property is considered a safer investment. Of course if the 'fiat money system' collapses, there is no reason to believe property rights will survive either. A paper property title is just a worthless as paper money if there is no government to enforce it.