Africans includes a huge variety of fish from Riveriane cichlids to Rift Lake cichlids, within the Rift Lakes, you have three different lakes to choose from, and within each lake there are a variety of forms to choose from as well. With a tank of this size, you have a whole lot of options, before we can offer you advice on compatibility, you need to make some decisions on what type of Africans you are interested in.
Most people who look at Africans are typically looking at Lake Malawi cichlids, as they are some of the ones which are most commonly available. Even within this group you have mbuna, peacocks, and Haps. While some can be kept together with the proper experience and care, others should not be. Since you are just starting out, it would be best if you selected a single type and then stuck to that type.
I suggest you start by googling images of mbuna, peacocks, and haps and make a decision of which group you would like to start with, and then we can go from there.
You will need lots and lots of rocks.