Fixing audio on a video

I am new to the youtube world and have been editing videos with premiere pro. I am trying to edit a new video and the audio is really messed up and I don't want to have to re-record. There are two separate video clips that I need the audio fixed on before I can begin editing. Is this something you can help me with? If you can, how long would it take?
Thank you so much for your time,
Faith