Hi, Desmond.
Yes, you can copy Styles. If you have your existing script with the styles you want open, go to the Styles panel on your Home ribbon, expand to see more, and in the Styles panel that comes up, find Style Manager, click that button. In the lower left corner of the Style Manager window will be Import/Export.
You can copy your Styles from your old document to your Normal.dot template, but you can also switch to your existing document (or a new Script Template, which would be a good suggestion if you're planning on writing scripts in the future). This
video does a pretty good job of showing you the steps; even though it's only four minutes you could probably skip the first minute where she's only highlighting the existing styles themselves.