Hi there, there were in total three motivations for European colonization which were God, glory, and gold.
Europeans had just recently arrived in Europe. Financially, culturally, scientifically, they had advanced... Basically, battles had ended due to newfound prosperity (Spain was financially more stable and with craving for power). Additionally, they had certain ideas about geography that led them to believe that there were unexplored regions of the planet. It's important to note that Christophe Colomb (let's call him Colomb) wasn't the smartest or most knowledgeable person in the room. He did really believe he was pursuing the "Indians," therefore it just so happens that he ended himself in America. His journal effectively captures the period's Europeans' avarice, sense of entitlement, and desire to "possess" the entire planet. Today, if we learned of a new location on Earth that hasn't yet been explored, we would act similarly and go exploring. Who could accomplish it? those with the most income, technology, and resources. Because it was the only region in the globe having those resources, Europe was the one investigating in the fifteenth century. It was unaware of the importance of every human existence (I'm generalizing here; not all people were thus illiterate), of distinctions, or of alternative points of view (religion, beliefs). Even though many people lost their lives on these earlier journeys, which weren't necessarily undertaken for the best reasons, they did help shape how Europe is now. Although there was existing diversity, respect, new ideals, and cultural interests somehow emerged. The world is what it is now because of history. Who can say what America would look like now if these discoveries hadn't taken place? This is a question for another time.
Thank you,
Eddie