You’re getting ahead of yourself. You haven’t actually started going to college yet 
Most college students change their major at least once before they finally settle on a a course of study. For chemical engineering, the school prestige is going to matter a little more than other STEM majors because the job demand is different, so you want to pick a school that can give you some good job placement. Just make sure it’s a school you can afford. At this point, don’t even give graduate school a second thought until your last year of college.