You definitely want to talk to Tango61. He'll point you in the right direction. And balzaccom, OregonMouse and ChrisFol have all told what else you really need to know. So, I'll point out that you're not too far from the Ozarks in Arkansas. You'll want to make your way up here if you enjoy your time out.
And remember, it's not about how many miles you hike. It's about being out there and enjoying yourself. So don't make it too much like work. Walk a mile and stop and rest. Stop at every scenic place you come to and spend some time enjoying it.
If you find a perfect spot to spend the night, or several nights, do it. Even if it's only a mile or two from your starting point.
Make it fun for your wife. If she's completely new to this, don't expect her to carry as much weight as you, hike as fast as you, or go as far as you.
Don't get me wrong, there are women here that can leave me in the dust, but my wife is not one of them. So whenever we go out hiking together I make sure we hike at her pace, and that she is enjoying herself too.
And whatever you do, don't expect her to do the cooking
Bill