$20k is hard and eliminates any business with consistent overhead (like rented space) or major equipment but I can try...
Domestic:
Local organic/natural food company. Either source organic meat or veggies and sell locally to chefs at restaurants, hotels, or food producers. Need less space and people than retail.
Fermented food (not kombucha, too saturated) business. Hipsters love that stuff.
Black American travel tour company - spend $5k traveling around Europe, South America, or Asia and creating relationships and a tour plan and then market to Black professionals.
Delivery/takeout only soul food restaurant near PWI college with a sizeable Black population. Equipment costs are a bytch though, even if leased
Local Black neighborhood bodega: run it yourself or hire people to do it. Maybe have them pay you per day like barber shops and let them keep the rest will help keep you from worrying about stealing and hookups. Security can be an issue though.
Domestic/International:
Spend $3-5k traveling to Asia or Europe and look at local retail, restaurant, or service ideas not available here that I could implement easily in the US with the rest of the money
International:
Set up a light manufacturing company for a local basic necessity that is mostly imported in Ghana, Senegal, Rwanda, or Tanzania. Maybe Caribbean too but they are more expensive.