Medical Education US

I AM IN MY FIRST SEMESTER IN COLLEGE, AND I WANT TO KNOW WHAT ARE SOME REQUIREMENTS FOR GETTING INTO MED SCHOOL. I WANT TO BECOME AN OB/GYN, AND I WANT TO KNOW WHAT GPA I SHOULD HAVE IN ORDER TO GET ACCEPTED WHEN I GRADUATE FROM COLLEGE? DO YOU UNDERSTAND? PLEASE HELP. PLEASE . SHOULD I MAJOR IN BIOLOGY?