Chances at getting into Columbia please HELP

<p>Hello people.
First off let me "introduce"" myself, I am currently a senior in High School, pretty low GPA :( but this is from my previous years I honestly slacked and I take full responsibility but last year and this year I have gotten better grades, specifically this year straight As. Still this was not enough to raise my GPA visibly. My SAT scores are average (580's-ish). I plan to go to community college for my first 2 years. Let's suppose I get a high GPA (3.7-3.8 or HIGHER), great extracurricular, you know all the bells and whistles, will my high school transcripts be detrimental to a great 2 years of college? Or will they realize I am capable of earning good grades? Also if you know anything regarding of courses I should take that they require or when in my second year should I apply? Oh and am I able o retake the SATs in college? I've taken them 3 times already...
Thank you so much!</p>