Paying rent or not will not effect your federal return. Unless you owned a home but you will still be able to enter that information even if you selected that you paid rent.
Whether you paid rent or not can effect your state return, though. You can either return to the personal information interview and go through all of the steps until you come to that question and change your answer OR if you are filling out the state return and it asks how much rent you paid you just enter zero. Either of those will solve the issue.