Prior to the wave of exploration, how did Europeans interact with and view outsiders?

Europeans interacted with people from the rest of the world primarily through trade. Trade goods made their way along a complex network of routes that connected Asia (as far away as China) and Africa to Europe. Europeans consumed luxury items such as silk (a commodity so valuable that the phrase "Silk Road" is used to describe these trade routes) and spices as early as the 200s BC. These trade routes seldom brought Europeans into direct contact with faraway peoples, as they involved a series of middle men, but they contributed to a view of China in particular as an exotic and astonishingly wealthy empire. On the other hand, when the Mongols began to threaten the eastern edges of Christendom, the east was understood to be the home of barbarians and savages. Africa was often portrayed as a land full of fearsome creatures and savage peoples, who practiced cannibalism. These views were not based on evidence, as few Europeans had contact with African peoples. So Europeans mythologized the outside world. One especially persistent myth was that of Prester John, supposedly a Christian king that ruled over a vast kingdom of considerable wealth. Some said the kingdom was in Africa, others in Asia. This passage from medieval English writer John Mandeville references both myths about Prester John and China, sometimes called Cathay in medieval times:

This Prester John hath under him many kings and many isles and many diverse folk of diverse conditions. And this land is full good and rich, but not so rich as is the land of the great Chan. For the merchants come not thither so commonly for to buy merchandises, as they do in the land of the great Chan, for it is too far to travel to. And on that other part, in the Isle of Cathay, men find all manner thing that is need to man--cloths of gold, of silk, of spicery and all manner avoirdupois. And therefore, albeit that men have greater cheap in the Isle of Prester John, natheles, men dread the long way and the great perils m the sea in those parts.

Europeans brought their attitudes toward the rest of the world when they began colonization, and their belief that they were superior to alleged savages and allegedly debauched peoples around the world played into their treatment of these people following the fifteenth century.
http://www.historyguide.org/earlymod/prester_john.html