Tell us in great detail exactly what you are doing and exactly what happens. Note the words "great detail", this is important.
Also please state your version NUMBER of Lightroom and your operating system.
(Confirm Save As)
! IMG_4956.JPG already exists.
Do You want to replace it?
! The File Named "IMG_4956.JPG cannot be replaced
Please choose a different name or different location
Version not sure how to tell but I just signed up and purchased it all it says is Adobe LightRoom CC 2015
Yes but what did you do, what exact steps did you follow, to cause this message to appear? How did you get there? You have to explain this in detail.
Also, as far as I know, there is no "Save As" in Lightroom. Are you sure this is happening in Lightroom?
could we face time for me to show you? because I'm just trying to open a new Catalog so I can start a new job
You could show me a screen capture ... but honestly I'm lost, I don't know what steps you performed to get these messages. Opening a new catalog would not produce these messages.