When you install a new theme, there are no problems with categories, products, prices or page content.
These data are not involved.
The only thing to consider is the compatibility between you Prestashop installation and our theme.
After installing one of our themes, most of the work is done.
Some modules remain adapted to your needs: you can follow the documentation provided and, if you have problems, you can let us know.
Last Updated: 29 Oct 2019