There has been the implicit assumption that, in general, Africans didn't leave the continent unless on a slave ship. There was, however, considerable exploration, migration, and movement undertaken by Africans for a variety of reasons, the main ones being trade, famine and climate change, and war. There is a plethora of theories about Pre-Columbian trans-oceanic contact with people in South America made by Polynesians, Chinese, Japanese, Arabs, Medieval Europeans,Welsh, and one that explorers from Africa also reached there. Africans were in the Roman Armies in Britain as generals and emperors; they were in Medieval and Renaissance Europe; they were present in many far-flung places and times.
There are suggestions each year made in these posts on how to organize ideas and get inspiration for travel: Thinking of Travel: Armchair and Otherwise (via books); Armchair Travel 2013 (via music); Thinking of Travel 2014: World War I (via visiting war memorials). Exploring museums, art museums and galleries, National Parks, libraries, theatres, concert halls are all terrific entries into new worlds.