If you are thinking about Mbuna, then you should get a bigger tank. Most need a minimum of 55g. Mbuna are the Yellow Labs/Electric Yellows, Pseudotropheus species, Red Zebras....those you find in a mixed African tank at the lfs
is one type that you could have in a 30g. You'd want a species tank and 1 male and about 5-6 females.
Or, you could have some Tanganyikan cichlids like shell dwellers
and a pair of Julidochromis
Requirements depend on which route you go....most are fine in sand and prefer hard, alkaline water.