RE: how long does it take to break in a new string..
Depending on the string of course, most strings will settle in somewhere around 200 shots.
Now.....for the strings rubbing together and making noise!!! That is NOT normal. Stop shooting or drawing the bow immediately and get it to a professional for observation. I can only guess what is wrong, like maybe the string is not the correct length or your cam's bushings are shot or something like that!
Once again, stop and get it to a professional.