Is a Job Required?
Investment property requires money. That money may come from a job, savings, an inheritance and so on. The job itself is not a requirement.
I will add that having money does not equate to the ability to manage it. Therefore, follow good investment practices and let your money work for you through an investment you understand. This stands in contrast to investing in something you know little or nothing about. Such investments tend toward greater risk in losing the money for many reasons.
Match the right investment property to your expertise, knowledge, budget, risk tolerance and so on. Then build the other resources you need to invest as successful as possible. Such resources include knowledge of the asset class, market savvy; tax, real estate, and management professionals, attorneys and others.
Finally, learn all you can about the investment property that interests you. That way you can assess risks and rewards.