In order to understand Kant, we have to know the philosophers before him. Therefore please do research on these two terms: "Empiricism" and "Rationalism".
Key question: their different accounts of knowledge, regarding the relationship between thinking beings (subjects) and existing things (objects). Do you agree with their explanation of knowledge?
Major philosophers: Hume for Empiricism and Leibniz for Rationalism
Methodology: Research on internet or in library