I applied to Cornell as a Mathematics major, but I changed my mind and want to pursue chemical engineering. If I get accepted, can I just change my major or not? What process do I have to go through?
You’ll need to internally transfer to the college of engineering. You’ll have to take anywhere from 1-3 semesters of engineering courses before you can transfer, and then your eligibility will be based on “curricular compatibility, cumulative grade point average, and acceptance to a major.”
https://www.engineering.cornell.edu/resources/advising/intransfer.cfm