Hi everyone. Does anyone know where I can find sound effects for Pivot?

You can't add sound effects to Pivot animations. You can export your animations to another program which does add sound, such as Flash, but no Pivot animation since the beginning of time has been improved by sound and I strongly recommend against it.

So don't add sound. Just music?

Most people use Windows Movie Maker 2.6 for adding sound into Pivot animations. (Many later versions do not play the animation in .gif files.) You can also use it for exporting Pivot files for YouTube.
If you want it, here's the download.
http://www.microsoft.com/en-gb/download/details.aspx?id=34

Use flash to add sounds to your pivot animations
its simple than using video editing program