Software :: Change/remove An Entry In Terminal?

I am a Mac user but do not know the technical or programming aspects of usage. A while ago I started with a new internet provider who attempted to give me a workaround to using bittorrenting without throttling (their service was being throttled by the parent line owner). The workaround involved putting some text into a Terminal window. I felt uncomfortable with this because i had heard you can really mess up your mac with Terminal if you dont know what your doing, but the guy i was talking to assured me this action he was leading me in was simple and wouldnt affect anything else. I did not finish the process he started me with (for fear of something going wrong), but I did enter enough text to wonder if its affecting my computer in some way. There are no signs of anything, but I'd rather make it as if I had never messed around with that to begin with, just incase. Its been about a month since this occured. I remember just closing the Terminal program and I havent touched it since. Can you please tell me what I can do to safely remove the entry?