All satellite data and derived products cover the whole of Africa. However, the amount of usable cloudless data and time depth may vary locally.
Several options are possible:
It is often helpful to know the coordinates of one of the points in the area. If it is a well-defined locality, a search in Wikipedia often provides access to the spatial coordinates of the place in the description inserted on the right of the page. Using Google Maps is also a good option.
Digital Africa Map has a feature that allows you to type the name of a locality and centre the map on it using the Microsoft Bing spatial search engine. You can copy/paste the coordinates to centre the map if you know the coordinates.
Once centred on the desired area, you can browse the catalogue and consult satellite images (Landsat, Sentinel, Modis) or derived products and explore the data.
Once the data of interest is imported into your work area, you select the images that only cover a particular area by clicking “filter by location” and selecting the point on the map.
By clicking on the buttons to the right of the date, you can display the available data and their date in a graph at the bottom of the map. You can view the data by clicking on the chart.
Please consult How to use the compare / separator tool in Maps? to compare images of different dates.
After selecting the notebook corresponding to the type of analysis that interests you, most notebooks are provided with a preview function of the study area, which accepts the spatial coordinates of this area as input.
The next step generally consists of loading the zone images using the load_ard function, which informs the number of available views according to the entry conditions.
You can access Explorer: https://explorer.digitalearth.africa
You can consult what data is available using https://docs.digitalearthafrica.org/en/latest/web_services/explorer_guide.html