I have to zoom the scene but the video is divided into many layers and files, is there away to zoom in everything without rendering the video first?
@Rquiem Yes there's a few ways to do that.
An fx like Picture in Picture (PinP) can be added to the preview window, (Video Output FX), this will affect the whole project,, a blue dot will indicate that an fx has been applied. the PinP can then be keyframed.
An fx can be added to an Adjustment track or an Adjustment event, again the fx will need to be keyframed.
An Adjustment event can be added for the full project & it's Pan/Crop can be keyframed.
There's Track Motion on the track header that could be used to zoom that track, or if the tracks below are Parent/Child grouped the Parent track's Track Motion can be keyframed, this will affect all tracks in that group.
I'm sure there's more options......
@Rquiem @Gid has given you many valid options, but I think that the easiest option, as you want the whole project zoomed, is to add a video track above your top track, add an adjustment event on that track that covers the whole project and use the pan/crop feature for this adjustment event to zoom in as far as you want. That level of zoom will extend for the whole project. As @Gid says, if you want different levels of zoom in places, you will need to keyframe the pan/crop.