In 2013 I needed to learn how to be a landlord and https://www.biggerpockets.com/renewsblog/2013/01/27/tenant-screening/
is what led me to Biggerpockets. Screening the tenant is one of the most important decisions in renting your house. They can make you a profit or destroy your place. If you have a nice place in a good neighborhood and get the right tenant, then it won't take much of your time. I have a great tenant, she takes care of the house, sends the rent on time or early each month. I talk to her once a year to renew the lease and maybe inspect the house once more during the year. Not much time involved after you get that right tenant. Getting that right tenant may take a dozen times screening phone calls by potential tenants and showing the house half a dozen times, or more.
Now if you have an older house in not great shape, then you may get several maintenance calls throughout the year and need a network of people to repair your property. If you don't have the time to find repair people or the network, then a property management company will have people they can get out to repair the property probably quicker than an individual can get the repair people to respond and maybe at less costs since they deal in volume.
If your property is local, I recommend doing it yourself to learn what is involved before hiring a property management company. But the learning process may take time away from your life that you would rather spend doing something else.