First things first; Don't freelance. The money is terrible and your source of income will be spotty at best. Instead, if you'd like to edit, I would encourage you to look at putting your skills to use in a law firm, a publishing house or even look into becoming a literary agent. Since you're in college, look at your campus writing center and offer to work as a volunteer or work study. Doing so will allow you to build upon working relationships with writers as well as allow you to hone your own skills outside of the classroom.
Best of luck to you in your future endeavors.