Heey i have downloaded the sony dvd templates..

And i am not the best to photoshop.

But my questien is. can i change the text. like which subtitels and sound.

If it is a text layer then you can double click on the layer. From there it will highlight the text. At that point you are able to change it to what you need it to be. If it is not a text layer and a rasterized text image then the best way to change it is to delete and recreate. Keep in mind that if it is a piece of a larger image just draw a selection box around what you want to replace and go from there.