Cut and paste clips in a track

Hi, I’m using Audacity 2.1.2 for my first time to mix and edit a simple backing track song with a overdubbed registered voice of my son.
I’ve regìstered some different voice tracks, and I’m trying to cut and paste them taking the best parts of any track, to create the definitive voice track.
I’ve some problems to cut and paste parts of clips between the several voice tracks. I’ve read in the manual that, if I copy a clip into a track in an enough empty space, all the other clips in the track will still in the same position (not be not moved on the right). In my case, also if a copy a short clip in an empty space of the track, all the other clips are moved on the right, loosing the sincronisation. Someone can help me? Many thanks to all.

When pasting a clip into a track, if there is a selection, the pasted audio will replace the selection.

Thus, if you paste a 1 second clip into a 2 second selection, the 2 second selection will be replaced by the 1 second clip, and all audio in the track after the selection will move to the left.
Similarly, if you paste a 2 second clip into a 1 second selection, the extra 1 second will push any following audio to the right.
It follows that if the clip being pasted is the same size as the selection into which it is being pasted, the clip will fit exactly into the selection and following audio will not move.

The easiest way to paste into a track without moving other clips, is to work from left to right, so that there is no audio in that track beyond where you are pasting. If you need to paste a clip earlier, add a new empty track and paste into that.

Another way, which will suit this particular job, is to change Audacity preferences so that pasting clips do not move other clips, then you can just click and paste, and so long as there is room for the new clip it will paste successfully (an error message is shown if there is not enough room).
To set this preference: “Edit menu > Preferences > Tracks Behaviour”, then de-select “Editing a clip can move other clips”
For most tasks, the default behaviour is more useful, so I’d recommend changing the preference back when you’ve completed this project.

Thank you Steve. I use other video editing softwares and I have to say that the clips management seems to be not very intuitive and a bit cumbersome in Audacity… anyway, I wil modify Preferences as suggested by you. Many thanks more.

This often catches people that come from video editing backgrounds. Audacity is not a video editor.
Handling clips is very natural for video as it is frame based, but audio is more fluid in that it is both sample based and time based. With video editing, if you want to paste a clip at a precise time position, the editor will automatically snap it to the nearest frame boundary, but in audio there are no frame boundaries, so audio clips may be pasted to any arbitrary time position. This underlying fact brings subtle differences to the way that editing audio works compared with editing video, which can take a bit of time to get used to.

I think that for the specific task you describe, that’s the best approach.