Yes, Black Walnut is native and supports lots of wildlife. The chemical naturally produced by its roots and other tissues, juglone, may or may not affect nearby plants -- scientific study is still inconclusive how impactful that is in the ground (versus in lab conditions) -- but you can find lists on various Extension web pages for species purportedly resistant to the affects of juglone.

A good first step is to assess the site conditions when trying to decide what to plant. You've mentioned the sun/shade exposures, but consider the soil conditions (walnut aside) like moisture retention and drainage. Does anywhere stay drier due to root competition and rain shielding from the tree canopy? Does a roof overhang block some rain, or does an overflowing gutter or roof downspout outlet put more water into certain planting areas after heavy rain? Working with existing conditions and choosing plants that tolerate or thrive in those conditions, rather than trying to change them to suit certain plants, is the simplest and usually the most successful approach. Therefore, if you have a notably wet or dry area of the yard, look for species known to have good wet-soil or drought tolerance, respectively. A handful of species are adaptable to both extremes.

Do deer visit the yard, either during the day or overnight? If so, choosing plants they usually avoid (those that are "deer-resistant") is best, though nothing is foolproof.

In general, there are more options for flowering plants (at least, those that are either showy in flower or which attract pollinators) in sunny sites than shady, but there are still several candidates for semi-shade or shade that will have decorative and wildlife-supporting blooms. We don't have an exhaustive list to share, but the resources below can help you find options.

Choose the largest-maturing plants first, as they will take up the most space and dictate where (and how many) other plants will fit around them, plus they can be placed where they either will or won't block a view (depending on your preferences). Very few of our native shrubs are evergreen, so for winter interest or year-round screening, take that into consideration if it's an important trait. Remember to plan on giving a shrub enough space to mature without much interference; that is, don't plan on having to prune the plant to fit into a limited space. Fortunately, many native plants have cultivars that are more compact-growing or dwarf than their wild counterparts. This feature doesn't necessarily make them less appealing or valuable for pollinators or other wildlife.

For pollinators, try to choose a range of species that will be in bloom at different times of year, to better serve species that are only active for part of the year (like pollen-specialist bees) or which need nectar or pollen sources all season long. Different flower styles (daisy-like flat faces, hanging trumpets, upright spikes, etc.) also support different pollinators. Even species not visiting flowers, or without access to many flowers (due to shade, maybe), will still benefit from the habitat generated by mixed-species plantings and plant diversity. Stem-nesting bees can make use of hollow-centered plant stems, and ground-nesting bees, moths, and other species will find shelter in leaf litter.

We don't have much information on species with either medicinal use or edible use to share (outside of some of the more conventional fruits and vegetables, very few of which are native). Blueberries and some brambles (blackberry/raspberry and kin) are locally or regionally native, as our pawpaw, elderberry, serviceberry, and American persimmon. Our Less Common Fruits for a Home Garden page covers some of these from the standpoint of cultivating them for a harvest.

Resources in our native plants group of web pages may be useful, but any plant lists they contain are just samplers to give gardeners some starter ideas; they are not exhaustive lists by any means. The linked pages below also may be helpful to browse species ideas, though they too are not exhaustive and focus on species that are showy and/or more readily sourced at garden centers, since a few of our native plants are hard to propagate.

• Native Plants for Wildlife Habitat and Conservation Landscaping: Chesapeake Bay Watershed by the U.S. Fish and Wildlife Service
  • you can use what is essentially a web version (and searchable and filterable) of this via the Alliance for the Chesapeake Bay's Native Plant Center
• Native Plants of Maryland by UMD Extension
• Landscaping with Native Plants by the Maryland Native Plant Society
• Native Plants for Northern Virginia (still applicable for most of Maryland)

These references maintain lists of native plant sources/suppliers, which might be helpful when you're ready to shop:

• Maryland Native Plant Society vendors list
• Mt. Cuba Center nursery resources

Miri