To customize individual pages, you need to go to the [your Project]/src/screens directory. This is where you will find the files for each page. For example, if you want to customize the home page, navigate to the screens folder and open the Home.js file.
Once opened, you’ll see that the page uses the <GridProductThumb> component to render each product category. So if you want to add a general styling for the <GridProductThumb> component, you have to update the appapp/components/product/GridProductThumb.js file.