In the United States, students do an undergraduate degree (first degree) to prepare for medical school. The most common choice at Cornell for students hoping to go to medical school is to major in biological sciences through the College of Arts and Sciences, the College of Agriculture and Life Sciences, or the College of Human Ecology. The College of Engineering is yet another option and prepares students well for the medical school application process. As long as undergraduates take the required pre-med courses, their major course of study doesn't have to be in the biological sciences. Instead, it could be a major in any of Cornell's undergraduate colleges or schools.
Unfortunately, admission to medical school in the U.S. for international students is quite limited. American medical schools have a strong preference for those who have received their undergraduate degree from a college or university in the U.S. However, admission policies vary somewhat based on whether an institution's funding is public or private, so it's worth checking with a few medical schools of interest.
For students considering pre-med, more information can be found on the Colleges, Schools, and Educational Pathways website in the Preparing for a Health Profession section. You may also find the How to Apply: First-Year International Applicants website to be a helpful resource.