@Ali Khalaf Based on what you have described, the best property to suit your goals is a 3/1 or 3/2 brick ranch with a basement and/or a garage in one of the following areas, J-Town (40299), Fern Creek (40291), Okolona / Hillview (40229), or along Dixie Highway (40272, 40258, and 40216). These are solid neighborhoods where you can expect to find responsible long-term tenants.
The primary threats to your long-term success are 1) water leaks of any kind and 2) tenant turnovers. The first is prevented by not deferring maintenance, tenant education and routine inspections. The latter is addressed by providing a house your tenants can live in and by providing superior customer service. In other words, if all you offer is price, they will move as soon as the next deal comes along. If you can do these things in a home that is flexible enough to accommodate them through various life changes you may have a tenant for life.
Obviously, your Property Manager or Turnkey Provider is key. When evaluating them make sure to ask questions such as how many properties they manage, how long they have been doing business, what type of property management software they use, what level of support staff exists and what systems they have in place to protect you. These should include a well-documented application-lease process, a good turnover process, and on and on.
I wish you the best of luck and please let me know if there is anything we can do to help you get started in your investing career!