Hey Jayhawkfan56 -

Try to keep whatever you do simple, something you can plant, it will thrive and is easy to maintain. Depending on the amount of sunlight it gets a dense groundcover that is strong enough to choke out weeds and will tolerate walnut would be good. Take a look around and see what desirable natives are already growing and encourage them. If it is sunny enough you can spread seeds of native grasses around along with other prairie plants. If you are more formal, put in a privet hedge and a lawn with a bench. A few big pots full of annual flowers for color and you're done. Everyone's tastes and ideas are different. Again go as simple as possible, using a few plant varieties in larger numbers together (such as lawn grass) wnen taking on larger areas to plant.

Hollies such as yaupons and dahoon would work there. Dogwood and redbud trees would look good too.

If the ground is acidic blueberries could be an option.

For vines, coral honeysuckle (not Japanese!), Carolina jessamine, and muscadine (wild grape) should be doable. Maybe some roses.