I am speaking in general becuase in order to know exactly
what you would like to do i would need a more detailed
description of your situation. But here goes anyway. If
you have a video track and an audio track you can use
ripple edits to keep everything in sync. For example if
you are editing a small section of the video out and this
causes the audio to be out of sync with the video then this
is your solution. If you wanted to delete a small section
out of a file you should engage ripple edits (ctrl+L, i
beleive this is on by default)and then make a time
selection. You can do this with the little triangles that
are above the timeline or by placing your cursor in an open
area of your project and then left clicking and draging
while holding down the left mouse button. You should then
be able to to hit the delete key on your keyboard and have
the entire project slide to the left.