What do you mean by saying the file is "in a whole format" ?
Are you in Storyboard Mode, and the whole video is seen as only 1 "Picture" ?
If this is the case, you must change to Timeline Mode. (The lower of the 3 'knobs' to the left of the 'Picture'.
Now I guess you have a long video, video on track 1 and sound on track 2.
Now right-click in track 1 and click on 'Scene recognition' (on top).
A new window comes up: At point 3 check that 'Cut at all markers' and 'Save all scenes as takes' are ticked.
Now click 'Start search' at point 1, this will take some time. When finished, click 'OK'.
Your film is now divided into many scenes.
Now go to 'File' and 'Save movie as' and give it a name.
Hope this is a help !