In Layout Setup, you can specify a tab order.
With script triggers, you can move the focus to specific fields when the user exits the field. (Terminate the script with Exit Script [False] to keep the layout's tab order from superseding your scripts use of go to field or go to object to put the cursor where you want it.)
when pressed it will copy field data from one layout and paste them to fields in another layout.
This does not sound like a good idea. Data on the first layout can be displayed on the second without having to copy/paste or otherwise make a new copy of the data. And if your script is moving the data by copying to the clipboard then you are creating additional, unnecessary potential problems for your user that are easily avoided by moving data via other methods.