We also don’t know for sure yet which Hawkman Aldis Hodge will play, although it’s reasonable to assume it’ll be the Carter Hall version given his ties to both Black Adam and the JSA in the comics.
No specific plot details for Black Adam have been revealed yet, although judging by the concept art shown at DC FanDome, it seems like the Justice Society’s clash with Black Adam will happen in the present day, though we’ll also look to the ancient past to learn how the man once known as Teth-Adam gained his powers, which was teased last year in Shazam!.