I messed up pretty bad in high school, is there any hope for me?

I know that universities look at high school scores, and this is where I am worrying. I botched my grades pretty bad and barely squeaked by. I'm assuming I did terrible on my SAT/ACT's as well.

I'm currently attending college at Black Hills State as an undecided; I'm just getting my generals out of the way. I won't be too thrilled if I have to get a major from a school that is not so well known. I want to change and become something greater, be somebody.

I'm 23 years old, made some horrible mistakes, wish I could do it all over again- is there any hope?

I'm doing half-way decent at where I am attending now; I have a 3.25 GPA, though I expect it to go up. I have no extracurricular activities, save for me writing for a few small gaming websites.

I want to get into a somewhat reputable college that will benefit me the most. What are the first steps I should take?