One of the must-do dining experiences in Sudan is dinner aboard one of the boats moored along the Nile. There are also good hotel restaurants where one can find good Arab-style or international cuisine. Otherwise, Sudan does not score high on high quality restaurants. Much of the dining in Sudan is done inside homes, and given the innate hospitality of the locals, you should be able to wangle an invitation or two!
The conservative and orthodox nature of the ruling regime rules out standard entertainment options in Sudan, especially in the conservative north of the country. This is reinforced by the general ban on alcohol. The capital is perhaps the only bet, where, apart from a few decent bars inside hotels, you must not miss the opportunity to watch the whirling dervishes perform their energetic, ecstatic, mystic dance every Friday afternoon (except Ramadan) in the Omdurman area, outside the Hamed an-Nil Mosque.