UChicago only considers CR + M, and your low GPA will probably hurt you, even if you do manage to pull off a 3.9 Junior and Senior year.
UChicago does not have business or engineering (except for molecular, and it’s brand new), and majoring in econ as some sort of substitute to business is not a good idea, the professors love making kids who try that suffer. I have heard that UChicago Careers in Business does a good job and you can take classes in Booth if you’re ambitious, so UChicago isn’t a totally horrible place to go to if you’re interested in business, but you should major in something you’re genuinely interested in.
To be blunt, why do you even want to come here? If the answer is the US News ranking, you don’t want to come here. I recommend doing some more research on the school.